Biochemical characterization of XXXX auxotrophs of @entity794 .

@entity73298 @entity376 @entity73299 @entity794
@entity376 biosynthesis in @entity794 has been studied by use of a series of @entity376 auxotrophs. The strains were isolated after chemical mutagenesis. The majority of these mutant strains were classified according to the enzymatic step found to be deficient. Specific enzyme assays as well as nutritional tests were used to group the organisms. The enzymes included were @entity73298 synthetase, @entity73298 reductase, @entity73299 epimerase, and @entity73299 decarboxylase. The accumulation of @entity73299 in certain mutants and the demonstration of @entity73298 synthetase and reductase provide the first detailed evidence that @entity794 utilizes the @entity73299 pathway for @entity376 biosynthesis. A cell-free system was used to study the regulation of these enzymes with the exception of @entity73299 epimerase. @entity376 repressed all of the enzymes tested. The repression appeared to be coordinate in nature. The data presented provide suggestive evidence that the @entity376 biosynthetic region in @entity794 constitutes an operon.
