title: Molecular Underpinnings of Nitrite Effect on CymA-Dependent Respiration in Shewanella oneidensis.
abstract: Shewanella exhibit a remarkable versatility of respiration, with a diverse array of electron acceptors (EAs). In environments where these bacteria thrive, multiple EAs are usually present. However, we know little about strategies by which these EAs and their interaction affect ecophysiology of Shewanella. In this study, we demonstrate in the model strain, Shewanella oneidensis MR-1, that nitrite, not through nitric oxide to which it may convert, inhibits respiration of fumarate, and probably many other EAs whose reduction depends on quinol dehydrogenase CymA. This is achieved via the repression of cyclic adenosine monophosphate (cAMP) production, a second messenger required for activation of cAMP-receptor protein (Crp) which plays a primary role in regulation of respiration. If nitrite is not promptly removed, intracellular cAMP levels drop, and this impairs Crp activity. As a result, the production of nitrite reductase NrfA, CymA, and fumarate reductase FccA is substantially reduced. In contrast, nitrite can be simultaneously respired with trimethylamine N-oxide, resulting in enhanced biomass.
authors: Institute of Microbiology and College of Life Sciences, Zhejiang University Hangzhou, China.
authors: Miao
authors: M
authors: Jin
authors: Institute of Microbiology and College of Life Sciences, Zhejiang University Hangzhou, China.
authors: Huihui
authors: H
authors: Fu
authors: Institute of Microbiology and College of Life Sciences, Zhejiang University Hangzhou, China.
authors: Jianhua
authors: J
authors: Yin
authors: Institute of Microbiology and College of Life Sciences, Zhejiang University Hangzhou, China.
authors: Jie
authors: J
authors: Yuan
authors: Institute of Microbiology and College of Life Sciences, Zhejiang University Hangzhou, China.
authors: Haichun
authors: H
authors: Gao
keywords: Shewanella; inhibition; nitrite; regulation; respiration