The images produced by Strynadka's team show the enzyme frozen in place by a powerful antibiotic called moenomycin. Moenomycin has been used for decades in animal feed to promote livestock growth. Bacteria have shown very little evidence of resistance to this antibiotic so far, and scientists think related compounds may be promising candidates for use in humans.
"This enzyme is an awesome target for antibiotics," said Strynadka. "We have a totally new understanding of how the enzyme works and how a very good animal antibiotic inhibits the enzyme." Although moenomycin is poorly absorbed by the human body, the new understanding of exactly how it interferes with bacterial enzyme function should help scientists design modified versions that are more suitable for use in people.
Understanding the structure of this enzyme should also speed up screening and design of new antibiotics, which are in constant demand as microbes continually evolve new ways to evade the drugs that researchers design to thwart them. The time it takes for bacteria to develop resistance to new antibiotics has been as short as one year for penicillin V and as long as 30 years for vancomycin.
Researchers attempting to solve the structure of this enzyme have struggled to recreate its cellular environment in the laboratory. But after much tinkering with different combinations of detergent, ions, and chemical additives, Strynadka's team was able to crystallize the enzyme so that it would diffract x-rays into a pattern that would ultimately reveal its natural
'"/>
Contact: Jim Keeley
keeleyj@hhmi.org
301-215-8858
Howard Hughes Medical Institute
9-Mar-2007