title: A leuC mutation leading to increased L-lysine production and rel-independent global expression changes in Corynebacterium glutamicum.
abstract: We previously found by transcriptome analysis that global induction of amino acid biosynthetic genes occurs in a classically derived industrial L-lysine producer, Corynebacterium glutamicum B-6. Based on this stringent-like transcriptional profile in strain B-6, we analyzed the relevant mutations from among those identified in the genome of the strain, with special attention to the genes that are involved in amino acid biosynthesis and metabolism. Among these mutations, a Gly-456-->Asp mutation in the 3-isopropylmalate dehydratase large subunit gene (leuC) was defined as a useful mutation. Introduction of the leuC mutation into a defined L-lysine producer, AHD-2 (hom59 and lysC311), by allelic replacement led to the phenotype of a partial requirement for L-leucine and approximately 14% increased L-lysine production. Transcriptome analysis revealed that many amino acid biosynthetic genes, including lysC-asd operon, were significantly upregulated in the leuC mutant in a rel-independent manner.
authors.affiliation: BioFrontier Laboratories, Kyowa Hakko Kogyo Co., Ltd., Machida, Tokyo 194-8533, Japan.
authors.forename: Mikiro
authors.initials: M
authors.lastname: Hayashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mizoguchi
authors.forename: Junko
authors.initials: J
authors.lastname: Ohnishi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Mitsuhashi
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Yonetani
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Hashimoto
authors.forename: Masato
authors.initials: M
authors.lastname: Ikeda
mesh_terms: D048230:Corynebacterium glutamicum / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D005285:Fermentation; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D020573:Genes, rel / Q000502:physiology; D005818:Genetic Engineering; D016680:Genome, Bacterial; D007218:Industrial Microbiology / Q000379:methods; D008239:Lysine / Q000096:biosynthesis*; D009154:Mutation; D014158:Transcription, Genetic / Q000235:genetics*
chemical_list: D008239:Lysine