Characterization of Escherichia coli men mutants defective in conversion of o-succinylbenzoate to 1,4-dihydroxy-2-naphthoate.
Four independent menaquinone (vitamin K2-deficient mutants ofEscherichia coli, blocked in the conversion of o-succinylbenzoate (OSB) to 1,4-dihydroxy-2-naphthoate (DHNA), were found to represent two distinct classes. Enzymatic complementation was observed when a cell-free extract of one mutant was mixed with extracts of any of the remaining three mutants. The missing enzymes in the two classes were identified by in vitro complementation with preparations of OSB-coenzyme A (CoA) synthetase or DHNA synthase isolated fromMycobacterium phlei. Mutants lacking DHNA synthase (and therefore complementing withM. phleiDHNA synthase) were designatedmenB, and the mutant lacking OSB-CoA synthetase (and therefore complementing withM. phleiOSB-CoA synthetase) was designatedmenE. ThemenBmutants produced only the spirodilactone form of OSB when extracts were incubated with [2,3-14C2]OSB, ATP, and CoA; the OSB was unchanged on incubation with an extract from themenEmutant under these conditions. Experiments with strains lysogenized by aλ mentransducing phage (λG68) and transduction studies with phage P1 indicated that themenBandmenEgenes form part of a cluster of four genes, controlling the early steps in menaquinone biosynthesis, located at 48.5 min in theE. colilinkage map. Evidence was obtained for the clockwise gene ordergyrA....menC-E⃰ -B-D, where the asterisk denotes the uncertain position ofmenErelative tomenCandmenB. The transducing phage (λG68) contained functionalmenB,menC, andmenEgenes, but only part of themenDgene, and it was designated λmenCE⃰ B(D).
D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial; D003066:Coenzyme A Ligases / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005798:Genes, Bacterial; D006836:Hydro-Lyases / Q000235:genetics*; D008242:Lysogeny; D009154:Mutation; D009284:Naphthols / Q000378:metabolism*; D010654:Phenylbutyrates / Q000378:metabolism*; D013389:Succinate-CoA Ligases / Q000235:genetics*; D014161:Transduction, Genetic
D009284:Naphthols; D010654:Phenylbutyrates; C024023:1,4-dihydroxy-2-naphthoic acid; C013691:o-succinylbenzoic acid; D006836:Hydro-Lyases; C021853:naphthoate synthetase; D003066:Coenzyme A Ligases; D013389:Succinate-CoA Ligases; C022693:O-succinylbenzoate - CoA ligase