title: Correlation between proton translocation and growth: genetic analysis of the respiratory chain of Corynebacterium glutamicum.
abstract: Corynebacterium glutamicum contains at least two terminal oxidases in the respiratory chain; cytochrome aa(3)-type cytochrome c oxidase and bd-type menaquinol oxidase. Thus, the chain has two branches of electron flow. The bcc-aa(3) branch translocates three protons per electron transferred, while the bd branch translocates only one. In this study, we constructed two mutant strains, lacking of either subunit I of the cytochrome c oxidase (DeltactaD) or subunits I and II of the quinol oxidase (DeltacydAB), and also plasmids to complement the deficient genes to investigate their effects on energy conservation and cell growth. We measured H(+)/O ratios of C. glutamicum wild-type and mutant cells grown aerobically. The H(+)/O ratio of the wild-type cells grown in the semi-synthetic medium was 3.94 +/- 0.30, while the value was 2.76 +/- 0.25 for the DeltactaD mutant. In contrast, the value was 5.23 +/- 0.36 for the DeltacydAB mutant. The cells grown in the LB medium showed higher value compared to that of cells grown in the semi-synthetic medium. The DeltactaD mutant grew less than the wild-type in LB medium, while they grew about equally in semi-synthetic medium. Correlation between bioenergetics and growth of C. glutamicum was significantly affected by the growth nutrients.
authors.affiliation: Department of Bioscience and Bioinformatics, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka, Fukuoka 820-8502, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Kabashima
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Kishikawa
authors.forename: Tatsuki
authors.initials: T
authors.lastname: Kurokawa
authors.forename: Junshi
authors.initials: J
authors.lastname: Sakamoto
mesh_terms: D000332:Aerobiosis; D048230:Corynebacterium glutamicum / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development*; D004579:Electron Transport / Q000235:genetics*; D003576:Electron Transport Complex IV / Q000235:genetics / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D011522:Protons
chemical_list: D011522:Protons; C082578:menaquinol oxidase; D003576:Electron Transport Complex IV