RRC ID 31375
著者 Nakayama T, Yonekura S, Yonei S, Zhang-Akiyama QM.
タイトル Escherichia coli pyruvate:flavodoxin oxidoreductase, YdbK - regulation of expression and biological roles in protection against oxidative stress.
ジャーナル Genes Genet Syst
Abstract E. coli YdbK is predicted to be a pyruvate:flavodoxin oxidoreductase (PFOR). However, enzymatic activity and the regulation of gene expression of it are not well understood. In this study, we found that E. coli cells overexpressing the ydbK gene had enhanced PFOR activity, indicating the product of ydbK to be a PFOR. The PFOR was labile to oxygen. The expression of ydbK was induced by superoxide generators such as methyl viologen (MV) in a SoxS-dependent manner after a lag period. We identified a critical element upstream of ydbK gene required for the induction by MV and proved direct binding of SoxS to the element. E. coli ydbK mutant was highly sensitive to MV, which was enhanced by additional inactivation of fpr gene encoding ferredoxin (flavodoxin):NADP(H) reductase (FPR). Aconitase activity, a superoxide sensor, was more extensively decreased by MV in the E. coli ydbK mutant than in wild-type strain. The induction level of soxS gene was higher in E. coli ydbK fpr double mutant than in wild-type strain. These results indicate that YdbK helps to protect cells from oxidative stress. It is possible that YdbK maintains the cellular redox state together with FPR and is involved in the reduction of oxidized proteins including SoxR in the late stages of the oxidative stress response in E. coli.
巻・号 88(3)
ページ 175-88
公開日 2013-1-1
DOI 10.1266/ggs.88.175
PII DN/JST.JSTAGE/ggs/88.175
PMID 24025246
MeSH Aconitate Hydratase / metabolism Amino Acid Motifs Base Sequence Escherichia coli / enzymology Escherichia coli / genetics Escherichia coli / metabolism* Escherichia coli Proteins / genetics* Escherichia coli Proteins / metabolism* Ferredoxin-NADP Reductase / genetics Ferredoxin-NADP Reductase / metabolism Gene Expression Regulation, Bacterial* Ketone Oxidoreductases / genetics* Ketone Oxidoreductases / metabolism* Molecular Sequence Data Mutagenesis Oxidation-Reduction Oxidative Stress* Paraquat / pharmacology Promoter Regions, Genetic Superoxides / metabolism Trans-Activators / genetics* Trans-Activators / metabolism*
IF 0.917
引用数 10
WOS 分野 GENETICS & HEREDITY BIOCHEMISTRY & MOLECULAR BIOLOGY
リソース情報
原核生物(大腸菌) JW1372-KC (ydbK) JW3895-KC (fpr) JW4023-KC (soxS) Mobile Plasmid (ydbK = nifJ)