WWW.NATURE.COM/NATURE
This press release is copyright Nature. VOL.446 NO.7134 DATED 22 MARCH 2007
This press release contains:
· Summaries of newsworthy papers:
Biochemistry: How to make vitamin B12
Materials: Brute force yields new molecules
Neuroscience: Emotion and moral judgements
Earth sciences: Ocean crust formation
Geology: The driving force of plate tectonics
Organic chemistry: Unprotected complexity
Evolutionary ecology: Understanding evolutionary bursts
· Mention of papers to be published at the same time with the same embargo
· Geographical listing of authors
Editorial contacts: While the best contacts for stories will always be the authors themselves, in some cases the Nature editor who handled the paper will be available for comment if an author is unobtainable. Editors are contactable via Ruth Francis on +44 20 7843 4562. Feel free to get in touch with Nature's press contacts in London, Washington and Tokyo (as listed at the end of this release) with any general editorial inquiry.
Warning: This document, and the Nature papers to which it refers, may contain information that is price sensitive (as legally defined, for example, in the UK Criminal Justice Act 1993 Part V) with respect to publicly quoted companies. Anyone dealing in securities using information contained in this document or in advanced copies of Nature’s content may be guilty of insider trading under the US Securities Exchange Act of 1934.
The Nature journals press site is at http://press.nature.com
· PDFs for the Articles, Letters, Progress articles, Review articles, Insights and Brief Communications in this issue will be available on the Nature journals press site from 1400 London time / 0900 US Eastern time on the Friday before publication.
· PDFs of News & Views, News Features, Correspondence and Commentaries will be available from 1400 London time / 0900 US Eastern time on the Monday before publication
PICTURES: While we are happy for images from Nature to be reproduced for the purposes of contemporaneous news reporting, you must also seek permission from the copyright holder (if named) or author of the research paper in question (if not).
HYPE: We take great care not to hype the papers mentioned on our press releases, but are sometimes accused of doing so. If you ever consider that a story has been hyped, please do not hesitate to contact us at [email protected], citing the specific example.
PLEASE CITE NATURE AND OUR WEBSITE www.nature.com/nature AS THE SOURCE OF THE FOLLOWING ITEMS. IF PUBLISHING ONLINE, PLEASE CARRY A HYPERLINK TO http://www.nature.com/nature
[1] Biochemistry: How to make vitamin B12 (pp 449-453; N&V)
Biochemists have worked out the last unknown step involved in the biosynthesis of vitamin B12 (cobalamin). Their discovery, reported in this week's Nature, solves a long-standing puzzle and reveals an unusual bit of biochemistry.
Vitamin B12 is one of the largest known non-polymeric natural products and is the only vitamin that is synthesized exclusively by microorganisms. But despite years of study, the biosynthesis of the lower portion of vitamin B12 is poorly understood.
Graham C. Walker and colleagues have solved the X-ray crystal structure of BluB, an enzyme that is needed in the final stages of vitamin B12 synthesis. They show that the enzyme uses molecular oxygen to cleave another molecule to form 5,6-dimethylbenzimidazole. The 5,6-dimethylbenzimidazole produced in that reaction is then incorporated into vitamin B12 by other enzymes.
The cannibalized molecule is called flavin mononucleotide and it is a cofactor — an organic molecule that binds to an enzyme and is needed for its catalytic activity. The enzymatic destruction of one cofactor to make another is quite unusual, and the authors suggest that BluB represents a new family of enzymes, called 'flavin destructases.'
CONTACT
Graham C. Walker (Massachusetts Institute of Technology, Cambridge, MA, USA)
Please contact co-author:
Christopher T. Walsh (Harvard Medical School, Boston, MA, USA)
Tel: +1 617 432 1715; E-mail: [email protected]
Steven E. Ealick (Cornell University, Ithaca, NY, USA) N&V author
Tel: +1 607 255 7961; E-mail: [email protected]
[2] Materials: Brute force yields new molecules (pp 423-427; N&V)
Chemists have designed a new type of molecule that changes identity when a mechanical force is applied. Apart from offering new ways to control chemistry, the effect might even result in mechanically responsive polymers that warn of impending structural failures, delay damage or even self-repair.
In most chemical reactions, reactants need to overcome an energy barrier before they are turned into products and the energy needed for this is usually provided by heat, light, pressure or electrical potential. In this week’s Nature, Jeffrey S. Moore and colleagues use mechanical force to achieve the same effect.
The team added carefully designed, force-sensitive units called ‘mechanophores’ to the middle of polymer strands. When a mechanical force is applied, the mechanophore undergoes a chemical reaction and turns into a different molecule.
It’s already known that mechanical forces can activate reactions by ‘tugging’ on reactant bonds, but usually this just ruptures the molecules. Critically, these new materials don’t break.
CONTACT
Jeffrey S. Moore (University of Illinois, Urbana, IL, USA)
Tel: +1 217 244 4024; E-mail: [email protected]
Virgil Percec (University of Pennsylvania, Philadelphia, PA, USA) N&V author
Tel: +1 215 573 5527; E-mail: [email protected]
[3] Neuroscience: Emotion and moral judgements (AOP)
DOI: 10.1038/nature05631
***This paper will be published electronically on Nature's website on 21 March at 1800 London time / 1400 US Eastern time (which is also when the embargo lifts) as part of our AOP (ahead of print) programme. Although we have included it on this release to avoid multiple mailings it will not appear in print on 22 March, but at a later date.***
The critical role played by part of the brain in making normal judgements of right and wrong is highlighted by a study in Nature this week. Patients with damage to an area of the brain involved in the normal generation of emotions have an abnormally ‘utilitarian’ reaction when presented with certain types of moral dilemma.
Antonio Damasio and colleagues studied six patients with focal lesions to the venteromedial prefrontal cortex (VMPC) on both sides of the brain. They presented them with a set of moral dilemmas that pit compelling considerations of aggregate welfare against highly emotionally aversive behaviours, such as having to decide whether to sacrifice one’s child in order to save a number of other people. The authors report that the patients tended to have a utilitarian reaction to these dilemmas – that is, they responded in a manner that favoured the greater good, despite the emotional significance of the decision.
The authors note that the effects of damage to the VMPC on emotion processing depend on context, and that their results are consistent with a model in which a combination of intuitive and rational mechanisms operate to produce moral judgements.
CONTACT
Antonio Damasio (University of Southern California, Los Angeles, CA, USA)
E-mail: [email protected]
Carl Marziali (Sciences Media Relations, University of Southern California, Los Angeles, CA, USA)
Tel: +1 213 740 4751; E-mail: [email protected]
Ralph Adolphs (California Institute of Technology, Pasadena, CA, USA) Co-author
Tel: +1 626 395 4486; E-mail: [email protected]
[4] Earth sciences: Ocean crust formation (pp 409-414)
The upwelling mantle that lies under the Earth’s crust at mid-ocean ridges is not symmetrical, a paper in this week’s Nature suggests. The surprising find helps refine our understanding of how the oceanic crust is formed.
New oceanic crust is produced at geologically active areas called mid-ocean ridges, where molten rock wells up and solidifies. Using seismic waves to image the mantle underneath one of these regions, Douglas R. Toomey and colleagues find that the zone of upwelling is unexpectedly skewed with respect to the axis of the ridge itself, and they suggest that this may govern segmentation of the East Pacific Rise — a long north–south region of seafloor spreading under the eastern Pacific Ocean.
CONTACT
Douglas R. Toomey (University of Oregon, Eugene, OR, USA)
Tel: +1 541 346 5576; E-mail: [email protected]
[5] Geology: The driving force of plate tectonics (pp 428-431)
The North American plate may be driven by mantle flow and deformation at the base of the continental crust, according to a report in Nature this week. David W. Eaton and colleagues studied the surface expression of the Great Meteor hotspot track to estimate the relative motion between the surface and the underside of the plate. The results provide new insights into the driving forces of plate motion.
Hotspots — relatively-fixed locations of active volcanism deep beneath the Earth’s surface — allow scientists to track the movements of plates as they pass over them, producing lines of volcanoes. The Great Meteor hotspot is one of the longest tracks in the Atlantic and reveals the movement of the North American plate over time. The authors used seismic images, geochronology and plate-motion reconstruction to compare the location and chronology of the hotspot track at the base and top of the North American lithosphere. They found that there is a displacement between the surface and deep parts of the tracks. This misalignment increases with age along the track, and is best explained by deformation in the mantle lithosphere beneath North America. They suggest that that motion of the plate is driven, rather than impeded, by viscous traction at the base of the plate.
CONTACT
David W. Eaton (University of Western Ontario, London, Canada)
Tel: +1 519 661 3190; E-mail: [email protected]
Please note that the author is travelling until 19 March but should have access to email during this time.
[6] Organic chemistry: Unprotected complexity (pp 404-408; N&V)
A simple and efficient approach to making large amounts of complex natural products from scratch is unveiled in this week's Nature.
Many bacteria naturally produce complex molecules with a broad range of biological activities, including antifungal, antibacterial and anticancer properties. But making large amounts to study in the lab or clinic can be problematic. Chemists often need to perform twenty or more steps, and even if each step is optimized to give high yields, very small amounts of the natural product are usually eventually obtained. Protecting groups are often needed to cover up particular parts of a molecule that might react with other reagents during the synthesis, but the addition and removal of these groups take time, add steps to the synthesis, and can reduce the end amount.
In this week's Nature, Phil Baran and his co-workers reveal an approach that slashes the number of steps needed to make several complex natural products. This approach avoids using protecting groups, and the authors were able to obtain gram — rather than milligram — quantities of the desired natural marine products. The team believes that this approach will facilitate the production of other medically relevant molecules in quantities that will enable biologists to study their mechanism of action and explore whether or not the natural products could be turned into potential therapeutic agents.
CONTACT
Phil Baran (Scripps Research Institute, La Jolla, CA, USA)
Tel: +1 858 784 7373; E-mail: [email protected]
John A. Porco Jr (Boston University, MA, USA) N&V author
Tel: +1 617 353 2493; E-mail: [email protected]
[7] & [8] Evolutionary ecology: Understanding evolutionary bursts (pp 432-435; 436-469; N&V)
The diversity of life is thought to have arisen through a series of bursts of evolution, referred to as adaptive radiations. Two studies published online in Nature this week identify predation and immigration history as key factors that influence this process.
Both groups manipulated microbial systems, which can evolve quickly over time, to study the processes influencing adaptive radiation. Justin R. Meyer and Rees Kassen looked at the effects of a predator, the single-celled eukaryote Tetrahymena thermophila, on the subsequent diversification of its prey, the bacterium Pseudomonas fluorescens. The presence of predators stifled the bacterium’s ability to diversify. The duo think that this may explain why adaptive radiation seems to occur after mass extinctions and on deserted islands, when predators are rare.
Tadashi Fukami and colleagues found that the sequence in which different species arrive in a given isolated habitat also affects subsequent bacterial diversification. And even small changes in immigration history can have a big knock on effect. Together, the findings show that the origins, extent, function and stability of biodiversity can only be understood by integrating ecology with evolution.
CONTACT
Justin R. Meyer (University of Ottawa, Canada) Author paper [7]
Tel: +1 613 889 1946; E-mail: [email protected]
Tadashi Fukami (University of Hawaii at Manoa, Honolulu, HI, USA) Author paper [8]
Tel: +1 808 956 6170; E-mail: [email protected]
Rosemary G. Gillespie (University of California Berkeley, CA, USA) N&V author
Tel: +1 510 642 3445; E-mail: [email protected]
ALSO IN THIS ISSUE…
[9] Relativistic effects in homogeneous gold catalysis (pp 395-403)
[10] Peptide bond formation destabilizes Shine–Dalgarno interaction on the ribosome (pp 454-457)
ADVANCE ONLINE PUBLICATION
***These papers will be published electronically on Nature's website on 21 March at 1800 London time / 1400 US Eastern time (which is also when the embargo lifts) as part of our AOP (ahead of print) programme. Although we have included them on this release to avoid multiple mailings they will not appear in print on 22 March, but at a later date.***
[11] Semaphorin 7A initiates T-cell-mediated inflammatory responses through a1b1 integrin
DOI: 10.1038/nature05652
[12] Foxp3 controls regulatory T-cell function by interacting with AML1/Runx1
DOI: 10.1038/nature05673
[13] Cell tracing shows the contribution of the yolk sac to adult haematopoiesis
DOI: 10.1038/nature05725
[14] Myc deletion rescues Apc deficiency in the small intestine
DOI: 10.1038/nature05674
GEOGRAPHICAL LISTING OF AUTHORS…
The following list of places refers to the whereabouts of authors on the papers numbered in this release. For example, London: 4 - this means that on paper number four, there will be at least one author affiliated to an institute or company in London. The listing may be for an author's main affiliation, or for a place where they are working temporarily. Please see the PDF of the paper for full details.
CANADA
London: 5
Ottawa: 7
Winnipeg: 5
FRANCE
Vandoeuvre les Nancy: 4
JAPAN
Kawaguchi: 12
Kobe: 13
Kyoto: 12
Osaka: 11
Tokyo: 12
NETHERLANDS
Utrecht: 11, 14
NEW ZEALAND
Auckland: 8
UNITED KINGDOM
Cardiff: 14
Glasgow: 14
UNITED STATES OF AMERICA
California
Berkeley: 9, 10
La Jolla: 6
Los Angeles: 3
Pasadena: 3
Stanford: 10
Hawaii
Honolulu: 4, 8
Illinois
Urbana: 2
Iowa
Iowa City: 3
Maryland
Baltimore: 11
Bethesda: 3
Massachusetts
Boston: 1
Cambridge: 1, 3, 11
Woods Hole: 4
Oregon
Eugene: 4
Washington
Seattle: 4
PRESS CONTACTS…
For North America and Canada
Katie McGoldrick, Nature Washington
Tel: +1 202 737 2355; E-mail: [email protected]
For Japan, Korea, China, Singapore and Taiwan
Mika Nakano, Nature Tokyo
Tel: +81 3 3267 8751; E-mail: [email protected]
For the UK/Europe/other countries not listed above
Helen Jamison, Nature London
Tel: +44 20 7843 4658; E-mail [email protected]
About Nature Publishing Group
Nature Publishing Group (NPG) is a division of Macmillan Publishers Ltd, dedicated to serving the academic, professional scientific and medical communities. NPG's flagship title, Nature, was first published in 1869. Other publications include Nature research journals, Nature Reviews, Nature Clinical Practice and a range of prestigious academic journals including society-owned publications. NPG also provides news content through [email protected] and scientific career information through Naturejobs.
NPG is a global company with headquarters in London and offices in New York, San Francisco, Washington DC, Boston, Tokyo, Paris, Munich, Hong Kong, Melbourne, Delhi, Mexico City and Basingstoke. For more information, please go to <www.nature.com>
