Structure of key enzyme in plague bacterium foundAugust 21, 2006Researchers at the National Institute of Standards and Technology (NIST) have solved the structure of a key enzyme from the bacterium responsible for plague, finding that it has a highly unusual configuration. The results may shed light both on how the bacterium kills and on fundamental cell signaling processes. The NIST team determined the three-dimensional shape of class IV adenylyl cyclase (AC), an enzyme found in plague bacteria - Yersinia pestis - by purifying and crystallizing the protein and using X-ray crystallography at the Center for Advanced Research in Biotechnology to resolve its configuration. Adenylyl cyclase is a fundamental enzyme found in one form or another in organisms ranging from bacteria to mammals. It synthesizes cyclic AMP (cAMP*), an important signaling molecule that in turn triggers a variety of cellular processes. Six distinct classes of AC are known, playing a wide variety of roles. AC-II is part of the anthrax bacterium's killing mechanism, for example, while AC-III triggers adrenaline release in humans. Shape plays an essential role in determining the biological function of a protein, but it's very difficult to determine for such large molecules. Three-dimensional structures are known for only two other forms of AC. The NIST experiments revealed that AC-IV has a shape completely different from the other two known shapes. AC-IV folds into a rare form of a barrel-like shape previously seen in only three other unrelated proteins. The purpose of AC-IV in plague is not well understood, but it may play a role in disrupting cell processes in the infected host. Plague is not as common as it was in the Middle Ages, when it killed millions, but the World Health Organization still logs about 1,000 to 3,000 cases a year, an average of 10 to 15 in the United States. It is rated as a highest category biothreat agent by the Centers for Disease Control and Prevention and the National Institute of Allergy and Infectious Diseases. Fundamental molecular data on this enzyme and its various forms may be critical to the development of defenses against plague and other pathogens, including Bacillus anthracis (Anthrax) and Bordetella pertussis (Whooping cough). Beyond that, structural and functional studies of AC-IV, with its unusual shape, may lead to deeper understanding of the cAMP signaling mechanism and other fundamental cellular processes. National Institute of Standards and Technology (NIST) |
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| Related Plague Bacterium Current Events and Plague Bacterium News Articles Where man boldly goes, bacteria follow Life in outer space is an absolute certainty, and it is likely to be more familiar than we might think, according to an article in the May issue of Microbiology Today. Ever since the start of the space race we have sent more than just satellites and astronauts into space: spacecraft are not routinely decontaminated and are teeming with microbial life. Scientists discover why plague is so lethal Bacteria that cause the bubonic plague may be more virulent than their close relatives because of a single genetic mutation, according to research published in the May issue of the journal Microbiology. How new diseases from insects hit people like the plague Scientists have traced the first steps in the way some new diseases emerge, and how harmless bacteria living in insects become dangerous disease-causing bugs which can affect humans, like the plague or anthrax. Researchers from the University of Bath are presenting their results today (Wednesday, 08 September 2004) at the Society for General Microbiology's 155th Meeting at Trinity College Dublin. Rapid Diagnostic Test For Plague An important step towards controlling bubonic and pneumonic plague may soon be possible with the use of a straightforward and accurate diagnostic test, according to authors of a study in this week's issue of THE LANCET. Plague is a flea-borne rodent disease that is occasionally transmitted to man, with around 3000-4000 cases annually in more than 20 countries, mainly in Africa. A rapid diagnostic test for the disease is urgently needed as current diagnosis is not possible until severe symptoms develop. Early diagnosis would also be crucial if the plague bacterium was used in biological warfare-pneumonic plague is always fatal unless treatment is initiated within 24 hours of disease onset. Su Ume'å scientist publishes new findings about origin of plague bacterium A team including researchers at the Total Defense Research Institute, NBC Defense, in Ume'å, Sweden, and the Department of Molecular Biology, Ume'å University, are publishing in this week's issue of Science new findings that show that the protein Ymt is of crucial importance for the capacity of the plague bacterium to survive and spread the plague via flea vectors. Professor Ã"¦ke Forsberg and visiting researcher Dr. Peter Cherepanov are studying the properties that enable the plague bacterium Yersinia pestis to cause life-threatening infections in animals and humans. Increased knowledge of the mechanisms that Y. pestis exploits to conquer the body's immune defense can make it Nature press release for 11 October issue [413519] BRAIN: FIRST LANGUAGE GENE FOUND (pp519-523; N&V) Researchers led by Anthony Monaco at the Wellcome Trust Centre for Human Genetics, University of Oxford, UK, have pinpointed the first gene to be definitively linked to language, in this week's Nature. The gene is mutated in the 'KE' family, some members of which have difficulty in controlling their lip and tongue movements, difficulty in forming words, and difficulty in using and understanding grammar. The gene codes for a 'transcription factor': a protein that switches genes on and off. The genes it interacts with might therefore signpost the way through the genetic network of language learning and use. It is known to be active in Nature press release for 19 October issue [407897] RELICS: OLDEST LIVING CREATURE EVER DISCOVERED? (pp897-900; N&V) This week, US researchers claim to have revived bacteria that have spent the last 250 million years in suspended animation. If true, the bugs smash the accepted record for the oldest living creatures ever discovered, previously held by bacteria a mere 25–40 million years old. The discovery raises the chances of life being able to survive long enough to travel between planets — our entire galaxy has revolved since the bugs that Russell Vreeland of West Chester University, Pennsylvania, and colleagues revived from Texas salt crystals last wriggled. The Bacillus bacteria that were isolated like to live in s More Plague Bacterium Current Events and Plague Bacterium News Articles |
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