Arogenate (pretyrosine) is an obligatory intermediate of L-tyrosine biosynthesis: confirmation in a microbial mutant.
Wild-type Brevibacterium flavum has been shown to possess arogenate dehydrogenase activity and to lack prephenate dehydrogenase, thereby providing presumptive evidence that arogenate (previously named "pretyrosine") is an obligatory intermediate of L-tyrosine biosynthesis. A similar enzymological pattern has been discerned in extracts made from wild-type cultures of various species of cyanobacteria. Application of rigorous molecular genetic criteria in confirmation of the exclusive role of arogenate in L-tyrosine synthesis was made possible by the isolation of an auxotrophic mutant exhibiting a nutritional requirement for L-tyrosine. The mutant was found to lack activity for arogenate dehydrogenase and to accumulate substantial amounts of arogenate behind the mutant block during starvation for L-tyrosine.
D000600:Amino Acids, Dicarboxylic / Q000378:metabolism*; D001951:Brevibacterium / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D053138:Cyclohexenes; D009154:Mutation; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000096:biosynthesis* / Q000378:metabolism
D000600:Amino Acids, Dicarboxylic; D053138:Cyclohexenes; D014443:Tyrosine; C015478:pretyrosine