title: Effects of the flrA regulatory locus on biosynthesis and excretion of amino acids in Escherichia coli B/r.
abstract: We have partially characterized phenotypic effects of an unusual amino acid regulatory locus, flrA, in E. coli B/r that alters the expression of the ilv and leu operons [Kline, E.L (1972) J. Bacteriol. 110:1127-1134]. This study demonstrated that a primary effect of the flrA7 mutation in haploid strains was overproduction of valine. In diploid strains (FflrA+/flrA7) this mutation resulted in excretion of valine, isoleucine, leucine, aspartate, threonine, glutamate, histidine and lysine. Increased excretion of amino acids by mutant strains might be explained by a membrane alteration or by flrA encoding a positive regulatory factor that affects the ilv operon and has pleiotropic effects on other amino acid operons.
authors.affiliation: Department of Microbiology, Clemson University, SC 29634.
authors.forename: B A
authors.initials: BA
authors.lastname: Nummer
authors.forename: S F
authors.initials: SF
authors.lastname: Barefoot
authors.forename: E L
authors.initials: EL
authors.lastname: Kline
mesh_terms: D015079:2-Isopropylmalate Synthase / Q000378:metabolism; D000409:Alanine / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics*; D005798:Genes, Bacterial / Q000235:genetics*; D005809:Genes, Regulator / Q000235:genetics*; D007532:Isoleucine / Q000378:metabolism; D007930:Leucine / Q000378:metabolism; D012356:RNA, Transfer, Leu / Q000378:metabolism; D046249:Transfer RNA Aminoacylation; D014633:Valine / Q000378:metabolism
chemical_list: D000596:Amino Acids; D012356:RNA, Transfer, Leu; D007532:Isoleucine; D015079:2-Isopropylmalate Synthase; D007930:Leucine; D014633:Valine; D000409:Alanine