title: Regulation of nitrite resistance of the cytochrome cbb3 oxidase by cytochrome c ScyA in Shewanella oneidensis.
abstract: Cytochrome c proteins, as enzymes to exchange electrons with substrates or as pure electron carriers to shuttle electrons, play vital roles in bacterial respiration and photosynthesis. In Shewanella oneidensis, a research model for the respiratory diversity, at least 42 c-type cytochromes are predicted to be encoded in the genome and are regarded to be the foundation of its highly branched electron transport pathways. However, only a small number of c-type cytochromes have been extensively studied. In this study, we identify soluble cytochrome c ScyA as an important factor influencing the nitrite resistance of a strain devoid of the bd oxidase by utilizing a newly developed transposon mutagenesis vector, which enables overexpression of the gene(s) downstream of the insertion site. We show that when in overabundance ScyA facilitates growth against nitrite inhibition by enhancing nitrite resistance of the cbb3 oxidase. Based on the data presented in this study, we suggest two possible mechanisms underlying the observed effect of ScyA: (1) ScyA increases electron flow to the cbb3 oxidase; (2) ScyA promotes nitrite resistance of the cbb3 oxidase, possibly by direct interaction.
authors.affiliation: Institute of Microbiology and College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Yin
authors.forename: Miao
authors.initials: M
authors.lastname: Jin
authors.forename: Haiyan
authors.initials: H
authors.lastname: Zhang
authors.forename: Lili
authors.initials: L
authors.lastname: Ju
authors.forename: Lili
authors.initials: L
authors.lastname: Zhang
authors.forename: Haichun
authors.initials: H
authors.lastname: Gao
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism; D045304:Cytochromes c / Q000235:genetics / Q000378:metabolism*; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004579:Electron Transport; D003576:Electron Transport Complex IV / Q000235:genetics / Q000378:metabolism*; D005798:Genes, Bacterial; D016296:Mutagenesis; D009573:Nitrites / Q000494:pharmacology*; D020592:Shewanella / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics
chemical_list: D001425:Bacterial Outer Membrane Proteins; D009573:Nitrites; D045304:Cytochromes c; C414443:cbb3 oxidase; D003576:Electron Transport Complex IV
keywords: Cytochrome c; Shewanella; nitrite resistance; the cytochrome cbb3 oxidase