A report on this finding appears in the September 1 issue of Molecular Cell.
The discovery also demonstrated that current textbooks use the wrong type of bacterium as a model to explain a critical biochemical step that most disease-causing bacteria use to make their membranes, according to Charles Rock, Ph.D., a member of the St. Jude Department of Infectious Diseases and senior author of the paper. As bacteria grow in size or divide, they must make additional membrane using a series of biochemical reactions. The first step in this process is the transfer of a fatty acid to a molecule called G3P. Bacteria then convert this molecule into a variety of other molecules called phospholipids, which are the building blocks of membranes.
"We identified a biochemical process that uses a previously unrecognized molecule as a raw material to make phospholipid," Rock said. "That discovery solved a mystery that has puzzled researchers for 25 years."
Scientists have used E. coli bacteria for many years as a model to understand how disease-causing bacteria make membrane phospholipids, but E. coli is an unsuitable model for most pathogens (disease-causing bacteria), according to Rock.
First, E. coli is a so-called gram-negative bacterium, while many of the pathogens researchers are interested in are gram-positive, Rock noted. Among those gram-positive organisms are Staphylococcus aureus, which causes skin infections and serious blood infections, and Streptococcus pneumoniae, which causes pneu
Source:St. Jude Children's Research Hospital