Social media tools and academic publishing
Alan J. Cann, Internet Consulting Editor, Annals of Botany; Department of Biology, University of Leicester, Leicester, UK
As publishing moves from print-focused (slow, inflexible, expensive) to content-focused (digital delivery, article-level metrics/discussion), there is an increasing need for publishers to communicate with their audiences in ‘adjacent spaces’ beyond the traditional medium of the journal or book. Social technologies will continue to evolve rapidly for the foreseeable future, so publishers need to acquire sufficient expertise to remain agile in this area in the face of future developments. I will describe the Annals of Botany low-cost online social media strategy, which is extending the reach of the journal to new audiences and new demographic groups. This includees blogs as distribution hubs for content via RSS, Twitter and Facebook, and emerging tools such as Flipboard which allow content discovery on new platforms such as tablet computers.
TED is a nonprofit organization devoted to "ideas worth spreading." They are mostly known because of their growing collection of fascinating talks about a wide array of topics, including science, art and anything in-between (or around). The talks are recorded and the videos are freely available at their website, where you can also find information about the speakers and interactive transcripts (including translations to various languages).
In this post I'm collecting links to all the TED videos I could find related to the microbial world.
Topics include: life in the deep oceans, medical mysteries, bacterial Esperanto, predicting pandemics, robots turned into microbiologists, new approaches to handle infectious diseases, looking for life on Mars and beyond, fungi that could save the world, bacteria that may have caused mass extinctions...
I also recommend reading this interview on the TED blog, where Seth Berkley commented on the same subject. I am copying here a few remarkable quotes:
I was very disappointed by public concerns that we ordered too much flu vaccine and that some might get wasted. (...) I think that both declaring this a global pandemic and accelerating vaccine production as quickly as possible were the right decisions. If you want to prepare a population for an emergency it means that you might ultimately spend some money that isn’t used.
That's a good point. Many criticisms have been raised in the last months against WHO decisions in relation to the recent flu pandemic. And some of those criticisms were undeserved, in my opinion.
In the interview, Berkley explained why so much effort was put on developing treatments --rather than preventive vaccines-- for AIDS. And he described the extraordinary work they're doing with the International AIDS Vaccine Initiative.
To the question "Are the members of the younger generation of scientists as invested in creating a vaccine as was the case 10 years ago or so?" he responded:
Sadly not. (...) The problem is not that young scientists don’t think vaccines are incredibly important, the problem is that it is seen as such a difficult problem, such a long-term problem that what they’re worried about is: Can they build a career on it? Can they get the types of breakthroughs they need in a rapid time frame that would make it a productive place to work?
It is disturbing that the "productivity" concept not only is doing harm to many researchers' careers but may also be slowing down the development of much-needed medical treatments...
Why not focus just on the treatment of infected people, and forget about an AIDS vaccine? Berkley explained:
(...) from a public policy point of view, there’s great expense involved in dealing with the epidemic through treatment and reaching people when they’re already infected. (...) But this is a long-term entitlement program, because once you put somebody on treatment, they have to get treatment for the rest of their lives and they develop conditions, they develop toxicity and they need other treatments. So, there’s almost a sense now that all of the bright lights of that unbelievable effort -- the unprecedented emergency program for AIDS relief, Bush’s triumph that people look on as being a great thing that he did, will create a demand that gets higher and higher and higher just to keep up with where we are.
So, making an effective vaccine against AIDS may be very difficult. But it is worth the effort.
And finally, as promised, this is the list of other TED videos related to the small living beings (in chronological order, newest first):
[Added October 15th, 2010 -- Eben Bayer: Are mushrooms the new plastic? "Product designer Eben Bayer reveals his recipe for a new, fungus-based packaging material that protects fragile stuff like furniture, plasma screens -- and the environment." July 2010. Found via MicrobiologyBytes.]
Magnus Larsson: Turning dunes into architecture. "Architecture student Magnus Larsson details his bold plan to transform the harsh Sahara desert using bacteria and a surprising construction material: the sand itself." July 2009.
Nathan Wolfe: hunting the next killer virus. "Virus hunter Nathan Wolfe is outwitting the next pandemic by staying two steps ahead: discovering deadly new viruses where they first emerge -- passing from animals to humans among poor subsistence hunters in Africa -- before they claim millions of lives." February 2009.
Bonnie Bassler: discovering bacteria's amazing communication system. "Bonnie Bassler discovered that bacteria "talk" to each other, using a chemical language that lets them coordinate defense and mount attacks. The find has stunning implications for medicine, industry -- and our understanding of ourselves." February 2009.
Hans Rosling on HIV: New facts and stunning data visuals. "Hans Rosling unveils new data visuals that untangle the complex risk factors of one of the world's deadliest (and most misunderstood) diseases: HIV. He argues that preventing transmissions -- not drug treatments -- is the key to ending the epidemic." February 2009.
Kary Mullis' next-gen cure for killer infections. "Drug-resistant bacteria kills, even in top hospitals. But now tough infections like staph and anthrax may be in for a surprise. Nobel-winning chemist Kary Mullis, who watched a friend die when powerful antibiotics failed, unveils a radical new cure that shows extraordinary promise." February 2009.
James Nachtwey fights XDR-TB. "Photojournalist James Nachtwey sees his TED Prize wish come true, as we share his powerful photographs of XDR-TB, a drug-resistant strain of tuberculosis that's touching off a global medical crisis. Learn how to help at http://www.xdrtb.org" October 2008.
Paul Stamets: six ways mushrooms can save the world. "Mycologist Paul Stamets lists 6 ways the mycelium fungus can help save the universe: cleaning polluted soil, making insecticides, treating smallpox and even flu." March 2008.
Peter Ward: Earth's mass extinctions. "Asteroid strikes get all the coverage, but "Medea Hypothesis" author Peter Ward argues that most of Earth's mass extinctions were caused by lowly bacteria. The culprit, a poison called hydrogen sulfide, may have an interesting application in medicine." February 2008.
Paul Ewald: can we domesticate germs? "Evolutionary biologist Paul Ewald drags us into the sewer to discuss germs. Why are some more harmful than others? How could we make the harmful ones benign? Searching for answers, he examines a disgusting, fascinating case: diarrhea.". March 2007. (I embedded this video in a previous post.)
Bill Stone explores the world's deepest caves. "Bill Stone, a maverick cave explorer who has plumbed Earth’s deepest abysses, discusses his efforts to mine lunar ice for space fuel and to build an autonomous robot for studying Jupiter’s moon Europa." "How do you take a robot and turn it into a field microbiologist?" March 2007.
Laurie Garrett on lessons from the 1918 flu. "In 2007, as the world worried about a possible avian flu epidemic, Laurie Garrett, author of "The Coming Plague," gave this powerful talk to a small TED University audience. Her insights from past pandemics are suddenly more relevant than ever." February 2007.
Penelope Boston says there might be life on Mars. "So the Mars Rovers didn't scoop up any alien lifeforms. Scientist Penelope Boston thinks there's a good chance -- a 25 to 50 percent chance, in fact -- that life might exist on Mars, deep inside the planet's caves. She details how we should look and why." February 2006.
Larry Brilliant wants to stop pandemics. "Accepting the 2006 TED Prize, Dr. Larry Brilliant talks about how smallpox was eradicated from the planet, and calls for a new global system that can identify and contain pandemics before they spread". February 2006.
Joe DeRisi solves medical mysteries. "Biochemist Joe DeRisi talks about amazing new ways to diagnose viruses (and treat the illnesses they cause) using DNA. His work may help us understand malaria, SARS, avian flu -- and the 60 percent of everyday viral infections that go undiagnosed." February 2006.
David Gallo on life in the deep oceans. "With vibrant video clips captured by submarines, David Gallo takes us to some of Earth's darkest, most violent, toxic and beautiful habitats, the valleys and volcanic ridges of the oceans' depths, where life is bizarre, resilient and shockingly abundant." February 1998.
During the last couple of years I've been collecting some YouTube videos related to microbiology. My microbiology playlist includes now over 70 videos of very different styles, including not only academic lectures and documentaries, but also animated movies and funny songs. You can watch many of these videos using the embedded viewer (see below).
This post is about pneumonia and pneumococci, fratricide at the cellular level, and a pretty protein. And there's a video too!
First things first. Pneumonia is a common disease characterized by inflammation of the lungs that can be deadly: 4 million people in the world die from it every year. Half of them are children under 5 years of age -- in fact, no other illness causes more deaths of children under age 5 worldwide. However, this is a preventable and treatable disease in most cases.
Many organisms can cause pneumonia, but the usual culprits are the bacteria Streptococcus pneumoniae (or pneumococcus, see above image) and, less frequently, Haemophilus influenzae type b (a.k.a. Hib). Safe and effective vaccines and antibiotics have been developed for these infections. Unfortunately, they are not commonly available in most developing countries, where pneumonia allies with poor nutrition, other illnesses (e.g. AIDS) and lack of resources to contribute to the cycle of poverty. To know more about the impact of pneumonia on world health and what can be done about it, I recommend listening to this podcast and visiting the World Pneumonia Day website.
My only direct contact with pneumococcus research was... hum... many years ago. As an undergraduate student, I spent two months at the Centro de Investigaciones Biológicas (CIB, Center for Biological Research) in Madrid, Spain, where I learnt how to cultivate pneumococci and some techniques for the study of lytic enzymes. These remarkable enzymes play a key role in bacterial physiology by cleaving, in a regulated fashion, specific linkages in peptidoglycan (that is, the highly cross-linked polymer that forms the bacterial cell wall). This apparently destructive activity is essential for cell wall turnover, and allows cell growth and division. Interestingly, the genomes of some bacteriophages (or bacterial viruses) also encode lytic enzymes, which the viruses use to break the cell wall and escape from its dying host after viral replication. These enzymes could be useful as antibacterial agents.
A few days ago I was happy to learn that a group of Spanish researchers --some of them from the CIB-- had solved the 3D structure of one of the pneumococcal lytic enzymes, called LytC. What I find remarkable is how the 3D structure elegantly explains the peculiar role that this protein plays during a process known as pneumococcal fratricide.
Some bacteria produce substances that kill surrounding microbes, and use the resulting dead bodies as a source of nutrients. Sometimes, killer and victim belong to the same species, or even they are siblings. In these cases, researchers speak of cannibalism or fratricide; although if you view microbial populations as coordinated, multicellular entities, then you may prefer to use the term programmed cell death.
Among pneumococci, some cells in a population become competent in response to certain signals; which means that they are able to take up DNA from their surroundings, and incorporate this genetic information into their own chromosome. This way, competent cells can acquire new inheritable abilities -- such as production of a new capsule type, or resistance to an antibiotic -- that can be very important for their survival (this was the underlying mechanism in the famous Avery-MacLeod-McCarty experiment that helped identify DNA as the hereditary material in cells).
But competent pneumococci do something else: they encourage non-competent siblings and other closely-related bacteria to commit suicide. They do this by releasing a particular lytic enzyme, called CbpD, that diffuses through the milieu and --somehow-- activates LytC and other lytic enzymes that are already present in the non-competent siblings. Cell wall weakening finally results in a big bang; that is, the explosion of the non-competent pneumococci. The materials released serve not only as nutrients and sources of genetic information (DNA), but also as virulence factors that help competent cells to survive in their human host.
The 3D structure of LytC now provides the clues to explain the enzyme's peculiar behaviour during pneumococcal fratricide. Have a look at the model of LytC on the left: ain't it a beauty? A substrate-binding module (in blue and green in the image) recognizes and binds the cell wall peptidoglycan, whereas a catalytic module (in red) is responsible for breaking a specific linkage in the substrate. Because of the unusual hook shape of the protein, the substrate-binding module and the catalytic module partially block each other. As a result, LytC cannot bind the highly cross-linked peptidoglycan that is predominant under normal circumstances. Only when CbpD or other lytic enzymes cut specific linkages in the cell wall, LytC is able to bind the 'loosened' peptidoglycan and comes into action -- with deleterious consequences for the non-competent pneumococci.
To make the story even more attractive (at least to me), the researchers bothered to produce a video that illustrates -- in a fascinating way -- the pneumococcal fratricide and the mechanism for LytC activation. Please watch it, the background music is nice too. The video includes some captions in Spanish, but I uploaded the video to YouTube and added English subtitles for a wider audience. I hope more researchers will get into the trouble of making visually attractive videos or presentations of their work (and make them freely available), it really makes a difference...
I also add here a nice composite image from the press release, just because I think it's so beautiful:
Reference for the 3D structure of LytC: Pérez-Dorado, I., González, A., Morales, M., Sanles, R., Striker, W., Vollmer, W., Mobashery, S., García, J., Martínez-Ripoll, M., García, P., & Hermoso, J. (2010). Insights into pneumococcal fratricide from the crystal structures of the modular killing factor LytC Nature Structural & Molecular Biology DOI: 10.1038/nsmb.1817
Vincent Racaniello is a well-known Professor of Microbiology at Columbia University Medical Center, New York. As a complement to his research and his classes on virology, he successfully uses different social media tools (blogging, podcasting, microblogging) to spread the love for viruses -- I mean, to teach the public about viruses (the kind that make you sick... or not). The following video is a recording of a great talk he gave at the Spring 2010 meeting of the Society for General Microbiology in Edinburgh, UK. In this presentation he explains -- in simple terms -- how he uses blogging, podcasting, and other social media tools for the popularization of virology.
I'm wondering if the talk could convince a few of the microbiologists in the audience to jump on the social media bandwagon...? Anyone?
You can read about the current state of the disease -- which kills almost two million people every year -- here: A world free of TB (Word Health Organization).
"If the right action is not taken right now, the continuing spread of MDR-TB [multidrug-resistant tuberculosis] could transform a disease that is curable with affordable medicines into a costly and deadly epidemic. If the right action is not taken right now, the continuing rise of XDR-TB [extensively drug-resistant tuberculosis] could take the world back to the era that predates the development of antibiotics, with nothing in hand to guarantee treatment success."
"The microbial world has given us a clear either-or situation. Either we tackle the problem now with rational and proven approaches, or we pay later with an epidemic of an airborne disease that renders our modern-day medicines and straightforward treatment regimens obsolete. This would truly be a tragedy, on a huge and costly scale, that should not happen."
Related links: - World TB Day.Twisted Bacteria, March 24th, 2008. - An 'open source' approach to drug discovery.Twisted Bacteria, July 1st, 2008. - Robert Koch y la tuberculosis.En Días Como Hoy, RTVE.es , 24 de marzo, 2010. [In Spanish] Se trata de un fragmento de un programa de radio (dos minutos y medio) en el que Nieves Concostrina nos recuerda, de forma amena, el momento en que el gran Robert Koch presentó al mundo la bacteria causante de esta enfermedad ("su bacilo").
The Poetry of Reality is the fifth installment in the Symphony of Science music video series. It features 12 scientists and science enthusiasts, including Michael Shermer, Jacob Bronowski, Carl Sagan, Neil deGrasse Tyson, Richard Dawkins, Jill Tarter, Lawrence Krauss, Richard Feynman, Brian Greene, Stephen Hawking, Carolyn Porco, and PZ Myers, promoting science through words of wisdom.
Additional links: - Symphony of Science, "a musical project headed by John Boswell designed to deliver scientific knowledge and philosophy in musical form." - Symphony of Science - The Poetry of Reality (An Anthem for Science), with Spanish subtitles (con subtítulos en castellano)
Lucky me, I am enjoying a few weeks with my partner in Geneva, Switzerland. During one of our first walks around the city, we noticed a big purple balloon on a small island in the Rhone river. Once we got closer (there is a bridge, no need to swim), we realized that this was no balloon --but a giant cell nucleus. The bright purple dome, 14 meters in diameter, hosts an exhibition entitled Génome: voyage au coeur du vivant (Genome: a journey to the centre of life), or The secret of life (this subtitle appears on the English-version booklet).
Inside the dome --the cell nucleus-- we enjoyed a multifaceted, imaginative and colourful (even psychedelic?) introduction to genetics and the human genome: from Rosalind Franklin to genome sequencing, from DNA replication to dimples. But let me quote from the first page of the booklet, where the purpose of the exhibition is clearly described:
Dear VISITOR
We would like to take a minute of your time to explain that
AN EXHIBITION IS FICTION
The wonderful world of the genome, which you will discover here, is an interpretation of reality. A purely scientific explanation could be difficult to understand. On the other hand an over-simplified one would not do justice to the astonishing ingenuity of nature.
You are about to enter a complex universe which is invisible to the naked eye. By using comparison and metaphor, a touch of poetry and humour, we hope that you will be both entertained and informed.
Please remember this message because it is true of all exhibitions; they are all interpretations of reality to a greater or lesser degree.
What an excellent description of what science communication to the general public should be! A delicate balance between (boring?) scientific information and (useless?) entertaining.
Did the Génome organizers accomplished their purpose? Well, they did it for us. You still have till February 28th to judge for yourself but, if you cannot make it to Geneva in time, the following video may give you a vague indication of what's going on inside the purple nucleus:
Génome: voyage au coeur du vivant has something for everyone. Science geeks may especially enjoy the awesome animations created by Drew Berry (including the one projected on the 360-degree screen over our heads!). Perhaps the name of this biologist and animator from the Walter & Eliza Hall Institute of Biomedical Research, Australia, does not ring a bell with you. But I'm almost certain that you have seen some of his award-winning films. See, for instance, the following selection:
The Génome booklet ends with some interesting "food for thought":
Perhaps we should take a philosophical view and agree that, in order to live life to the full, we humans will always need uncertainty!
Well put. And this goes far beyond genetics and evolution...
A long time ago I added a video bar on the side of my blog (only on main page), under the following title: "Microbial" videos (live search). The thing uses some microbial-related terms to automatically retrieve videos from YouTube, Google Videos and the like. This way I found a very nice "brickfilm" that is displayed below. The brickfilm (a stop-motion animation using LEGO or other brick-like elements) is called Great microbiologists and takes a funny look at microbiology and its early history. It was made in 2006 to commemorate the graduation of two students from the Microbiology department at Colorado State University. I hope you enjoy the video as much as I do.
Notes and related links:
- About the video bar: "Microbial" videos (live search) The video bar is only visible on the main page of my blog, not on individual posts. It uses a Google AJAX Search API (whatever this may be) that can be found at Video Bar Wizard. You can use this "wizard" to add a similar video bar to your blog and display either a live search (as I did) or a set of selected channels. Of course, the automated search may retrieve both relevant and totally irrelevant videos, depending on your choice of search terms. - About the brickfilm "Great microbiologists" Watch the video at YouTube Read more information and download the film at Brickfilms.com
In this short Disney film (The Winged Scourge, 1943), the Seven Dwarfs teach us how to protect ourselves from the mosquitoes that transmit malaria. But some of their methods may not be quite advisable today...
Thanks to MicrobeWorld for letting me know about this video!
A collection of old Disney documentaries (including this one) can be viewed at thelostdisney channel on YouTube.
The following videos are short educational films made in the 1940s and 1950s and provide some basic knowledge on infectious diseases and microbiology. How much has this basic knowledge changed after half a century? Which specific statements in the videos should be changed (and why) if you wanted these films to comply with today's microbiology? Please leave any comments here.
The three videos were uploaded onto Google Video by A/V Geeks. They have been digitizing thousands of TV commercials held at Duke University’s Hartman Center for Advertising.
THE INFECTION HAS TAKEN HOLD. Nearly 30,000 individuals have already been exposed to the INFECTIOUS exhibition in the Science Gallery. If you are brave enough to enter the containment zone on Pearse Street you are advised to wear protective clothing. INFECTIOUS is a major new exhibition exploring mechanisms of contagion and strategies of containment through science and art including a live epidemic simulation, an opportunity to have your DNA swabbed from your cheek and analysed and to get up close and intimate with a Petri dish as you cultivate the bacteria from your lips in our Kiss Culture experiment.
The following slidecast (that is, a slideshow including audio) is an excellent presentation by Mary Canady and William Gunn on social media for scientists. Topics covered: LinkedIn, Twitter, social bookmarking (delicious, citeulike, Mendeley), FriendFeed, science blogs. If you are a scientist and you think social media is completely useless for you as a researcher... well, you are wrong and must watch this!
The following videos are two short documentaries made by students in the MIT Graduate Program in Science Writing. Both films refer to a recent discovery of new antibiotics by scientists at the Massachusetts Institute of Technology and the University of Florida. But, please, don't say: "bah, another antibiotic discovering, so boring". What makes this an interesting story is not the particular antibiotics themselves (we'll see if they ever become useful), but the way they were discovered. Or should we say "created"? It's been known for some time that the genomes of many microbes contain genes putatively coding for the production of many small molecules. Some of these molecules may have antibiotic, anticancer or other potentially useful activities. By looking at the genomic DNA sequence, scientists can often predict that such a microbe has the potential to produce specific metabolites, belonging to defined structural classes (polyketides, non-ribosomal peptides, glycosides, etc.). However, very often, the predicted metabolites are not detected when the microbe is cultured under standard laboratory conditions. Why is this? The usual explanation is that these molecules are only produced under specific circumstances that the microorganism faces in its natural environment.
With this idea in mind, the above mentioned researchers tried to find antibiotics in the cultures of a bacterium called Rhodococcus fascians (let's call it "Rhodo"). Rhodo belongs to a group of bacteria known as actinomycetes, which are well-known antibiotic producers and whose genomes are rich in information coding for the synthesis of potentially useful metabolites. The scientists cultured the microorganism under a variety of conditions: they tried both standard and unusual ones (starvation, sub-optimal temperatures or culture media, etc.). However, no antibiotic activity was ever detected.
So, they tried to "stress" Rhodo by adding another microbe in the same flasks: the name of the second partner was Streptomyces padanus ("Strepto", for short). Strepto produces a potent antibiotic (actinomycin) that kills bacteria such as Rhodo. So, what was the point? Rhodo died in all flasks, didn't it? Well, not in all of them. In one particular flask (out of hundreds), Rhodo not only survived but actually exterminated Strepto! The "Super-Rhodo" did this by producing a new antibiotic substance, never seen before. Moreover, Super-Rhodo was able to do this thanks to a piece of DNA that Rhodo stole from Strepto!
Both documentaries refer to the same story, but they use remarkably different styles. Please watch both of them, and post a comment if you want to share your thoughts (about them or about the story).
The first video is War in a Petri Dish, by Grace Chua, Allyson Collins, and Lissa Harris:
There are some scientific aspects that may need some clarification. The initial idea was that Rhodo contained the genetic potential to make antibiotics, and the genes responsible for this were only "switched on" under certain unknown circumstances. This might be correct, but the mentioned results don't clearly validate it. When Rhodo faced a Strepto attack, it simply died. The only survivor (and now a killer itself), Super-Rhodo, had acquired genetic material from its enemy. This extra piece of DNA was essential for production of the new compounds. Although full details have yet to be published, it is not clear if the transferred DNA contained all, or some, of the genes coding for biosynthetic enzymes for antibiotic production. The new antibiotics are not related to actinomycin; however, it is possible that Strepto is able to produce them, in addition to actinomycin (again, under certain unknown circumstances...). Alternatively, the real effect of the extra DNA might be just regulatory, coding for some factor that induced the "switching on" of Rhodo's own genes. We'll wait for the answers to these doubts.
Scholar article: K. Kurosawa, I. Ghiviriga, T.G. Sambandan, P.A. Lessard, J.E. Barbara, C. Rha, A.J. Sinskey (2008). Rhodostreptomycins, Antibiotics Biosynthesized Following Horizontal Gene Transfer from Streptomyces padanus to Rhodococcus fascians Journal of the American Chemical Society, 130 (4), 1126-1127 DOI: 10.1021/ja077821p
Polyketides are a class of natural products isolated from microbes, plants and invertebrates which includes an impressive number of clinically effective drugs with diverse activities. To name a few examples: erythromycin (antibiotic), rapamycin (immunosuppressive), amphotericin (antifungal), avermectin (antiparasitic), and doxorubicin (anticancer). As other natural products do, polyketides may play disparate roles in the producing organisms, from defensive weapons (inhibiting growth of competitors, or acting against predators) to signaling molecules (working as messengers between social organisms). In Mycobacterium tuberculosis, some polyketides are key intermediates in the synthesis of complex lipids. These lipids are important components of the unusually thick cell envelope, and help the microbe to be a successful pathogen. Therefore, the study of polyketide synthesis in this bacterium may lead to the design of specific inhibitors as new anti-mycobacterial drugs. Polyketides are produced through a stepwise condensation of simple carboxylic acid precursors, resembling fatty acid biosythesis. This task is performed by enzymes known as polyketide synthases (PKSs). There are several types of PKSs, from relatively simple proteins to large multienzymatic complexes possessing tens of catalytic sites. They use any of two general mechanisms: (1) modular — in which each set of catalytic sites is used only once during the biosynthetic process, and (2) iterative — in which the same set of active sites is used repeatedly. This week in PLoS Biology, Rajesh Gokhale and colleagues present their research involving a peculiar PKS from M. tuberculosis. The PKS12 protein is encoded by the largest gene in the microbe's genome, and participates in the synthesis of an antigenic phosphoglycolipid. Most remarkably, this PKS appears to use a new hybrid "modularly iterative" mechanism for polyketide synthesis. Several molecules of the PKS12 protein join together to form a supramolecular assembly, which performs repetitive cycles of iterations. The protein assembly is formed by specific intermolecular interactions between N- and C-terminus linkers. This study provides another example of the catalytic and mechanistic versatility of PKSs — natural product biosynthesis is an inexhaustible source for new biochemistry!
Citation (open access): Chopra T, Banerjee S, Gupta S, Yadav G, Anand S, Surolia A, Roy RP, Mohanty D, Gokhale RS (2008). Novel intermolecular iterative mechanism for biosynthesis of mycoketide catalyzed by a bimodular polyketide synthase. PLoS Biology 6(7), e163. DOI: 10.1371/journal.pbio.0060163
Image: model of the PKS12 protein, modified from Figure 5 of the cited article.
A video from YouTube (Microorganism Spacial Journey) showing microscopic images of microbes and other tiny beasts, accompanied by a very relaxing music.
"The Federation of American Scientists (FAS) presents Immune Attack™, an educational video game that introduces basic concepts of human immunology to high school and entry-level college students. Designed as a supplemental learning tool, Immune Attack aims to excite students about the subject, while also illuminating general principles and detailed concepts of immunology."
