RRC ID 3274
著者 Kanai T, Takahashi K, Inoue H.
タイトル Three distinct-type glutathione S-transferases from Escherichia coli important for defense against oxidative stress.
ジャーナル J Biochem
Abstract Previously, we characterized glutathione S-transferase (GST) B1-1 from Escherichia coli enzymologically and structurally. Besides GST B1-1, E. coli has seven genes that encode GST-like proteins, for which, except SspA, neither biological roles nor biochemical properties are known. Here we show that the GST-like YfcF and YfcG proteins have low but significant GSH-conjugating activity toward 1-chloro-2,4-dinitorobenzene and GSH-dependent peroxidase activity toward cumene hydroperoxide. Analysis involving site-directed mutagenesis suggested that Ser16 and Asn11 were important for the activities of YfcF and YfcG, respectively. On the contrary, no residue around the catalytic site of GST B1-1 has been demonstrated to be essential for catalytic activity. Deletions of the gst, yfcF, and yfcG genes each decreased the resistibility of the bacteria to hydrogen peroxide, which was recovered by transformation with the expression plasmid for the deleted enzyme. The inactive YfcF(S16G) and YfcG(N11A) mutants, however, could not rescue the knockout bacteria. Thus, E. coli has at least three GSTs of distinct classes, all of which are important for defense against oxidative stress in spite of the structural diversity. This seems consistent with the hypothesis that GSTs constitute a protein superfamily that has evolved from a thioredoxin-like ancestor in response to the development of oxidative stress.
巻・号 140(5)
ページ 703-11
公開日 2006-11-1
DOI 10.1093/jb/mvj199
PII mvj199
PMID 17018556
MeSH Amino Acid Sequence Circular Dichroism Escherichia coli / drug effects Escherichia coli / enzymology* Escherichia coli Proteins / biosynthesis* Glutathione Transferase / biosynthesis Glutathione Transferase / metabolism* Hydrogen Peroxide / antagonists & inhibitors Molecular Sequence Data Mutagenesis, Site-Directed Oxidative Stress / drug effects* Sequence Alignment
IF 2.476
引用数 47
WOS 分野 BIOCHEMISTRY & MOLECULAR BIOLOGY
リソース情報
原核生物(大腸菌) JW1627-KC JW2298-KC JW2299-KC ME9062(BW25113)