. | . |
Quest For Designer Bacteria Uncovers A Spy
Ann Arbor, MI (SPX) Feb 21, 2011 Scientists have discovered a molecular assistant called Spy that helps bacteria excel at producing proteins for medical and industrial purposes. Bacteria are widely used to manufacture proteins used in medicine and industry, but the bugs often bungle the job. Many proteins fall apart and get cut up inside the bacteria before they can be harvested. Others collapse into useless tangles instead of folding properly, as they must in order to function normally. A research team led by James Bardwell, who is a professor of molecular, cellular and developmental biology and of biological chemistry, as well as a Howard Hughes Medical Institute investigator, at the University of Michigan, developed a way to coerce bacteria into making large quantities of stable, functional proteins. Then, in exploring why these designer bacteria were so successful, the scientists discovered the molecular helper, Spy. The research is scheduled for online publication Feb.13 in the journal Nature Structural and Molecular Biology. In the first phase of the research, the team designed biosensors that directly link protein stability to the antibiotic resistance of bacteria. When a poorly folded, unstable protein is inserted into the middle of the biosensor in a bacterium, it disrupts the bug's resistance to antibiotics. When the protein is stabilized, resistance is restored. The researchers inserted a particularly unstable protein into Escherichia coli (E. coli), which forced the bacteria to either adapt by improving protein stability or die when exposed to antibiotics. Through a "directed evolution" experiment, in which the scientists selected colonies with increasing antibiotic resistance-and increasing protein stability-the team generated designer bacteria that produced up to 700 times more of the previously unstable protein. "It is exciting to realize that if even bacteria are asked in the right way, they can come up with good solutions to hard problems," said postdoctoral fellow Shu Quan, who spearheaded the work. In looking to see why the designer bacteria were so much better at producing proteins, the scientists found that the efficient microbes were making much more of a small protein called Spy. Further study showed that the cradle-shaped Spy aids in protein refolding and protects unstable proteins from being cut up or sticking to other proteins. "Our work may usher in an era of designer bacteria that have had their folding environment customized so that they can now efficiently fold normally unstable proteins," Bardwell said. The work was conducted in Bardwell's lab at U-M. Mirek Cygler's laboratory at McGill University solved the structure of the Spy protein. In addition to Bardwell, Quan and Cygler, the paper's authors are masters students Philipp Koldewey and Stephan Hofmann; undergraduate students Nadine Kirsch and Jennifer Pfizenmaier; postdoctoral research associates Tim Tapley, Linda Foit and Guoping Ren; associate professor Ursula Jakob and associate professor Zhaohui Xu; all of U-M; and Karen Ruane and Rong Shi of McGill University.
Share This Article With Planet Earth
Related Links Nature Molecular and Structural Biology University of Michigan Darwin Today At TerraDaily.com
Indonesia sending apes to 'killing field': NGO Jakarta (AFP) Feb 17, 2011 More than 1,000 captive orangutans set for release into the wild on Borneo island are being sent into a "killing field" of illegal logging and poaching, conservationists said Thursday. Indonesia has reserved 86,450 hectares (214,000 acres) of forest in Muara Wahau, East Kalimantan province, for the rehabilitation of 1,200 captive big apes over the next four years. But the independent Cen ... read more |
|
The content herein, unless otherwise known to be public domain, are Copyright 1995-2010 - SpaceDaily. AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement |