Low resolution solution structure of an enzymatic active AhpC 10 :AhpF 2 ensemble of the Escherichia coli Alkyl hydroperoxide Reductase

2016 ◽  
Vol 193 (1) ◽  
pp. 13-22 ◽  
Author(s):  
Neelagandan Kamariah ◽  
Wilson Nartey ◽  
Birgit Eisenhaber ◽  
Frank Eisenhaber ◽  
Gerhard Grüber
Keyword(s):  
Escherichia Coli ◽  
Solution Structure ◽  
Low Resolution ◽  
Alkyl Hydroperoxide Reductase ◽  
Alkyl Hydroperoxide

scholarly journals Role of OxyR as a Peroxide-Sensing Positive Regulator in Streptomyces coelicolor A3(2)

2002 ◽  
Vol 184 (19) ◽  
pp. 5214-5222 ◽  
Author(s):  
Ji-Sook Hahn ◽  
So-Young Oh ◽  
Jung-Hye Roe
Keyword(s):  
Escherichia Coli ◽  
Streptomyces Coelicolor ◽  
Cumene Hydroperoxide ◽  
Exponential Phase ◽  
Alkyl Hydroperoxide Reductase ◽  
Direct Role ◽  
Positive Regulator ◽  
Alkyl Hydroperoxide ◽  
Serovar Typhimurium ◽  
Genes Encoding

ABSTRACT Genes encoding a homolog of Escherichia coli OxyR (oxyR) and an alkyl hydroperoxide reductase system (ahpC and ahpD) have been isolated from Streptomyces coelicolor A3(2). The ahpC and ahpD genes constitute an operon transcribed divergently from the oxyR gene. Expression of both ahpCD and oxyR genes was maximal at early exponential phase and decreased rapidly as cells entered mid-exponential phase. Overproduction of OxyR in Streptomyces lividans conferred resistance against cumene hydroperoxide and H2O2. The oxyR mutant produced fewer ahpCD and oxyR transcripts than the wild type, suggesting that OxyR acts as a positive regulator for their expression. Both oxyR and ahpCD transcripts increased more than fivefold within 10 min of H2O2 treatment and decreased to the normal level in 50 min, with kinetics similar to those of the CatR-mediated induction of the catalase A gene (catA) by H2O2. The oxyR mutant failed to induce oxyR and ahpCD genes in response to H2O2, indicating that OxyR is the modulator for the H2O2-dependent induction of these genes. Purified OxyR protein bound specifically to the intergenic region between ahpC and oxyR, suggesting its direct role in regulating these genes. These results demonstrate that in S. coelicolor OxyR mediates H2O2 induction of its own gene and genes for alkyl hydroperoxide reductase system, but not the catalase gene (catA), unlike in Escherichia coli and Salmonella enterica serovar Typhimurium.

Low resolution solution structure of the apo form of Escherichia coli haemoglobin protease Hbp

2002 ◽  
Vol 315 (5) ◽  
pp. 1179-1187 ◽  
Author(s):  
David J. Scott ◽  
J.Günter Grossmann ◽  
Jeremy R.H. Tame ◽  
Olwyn Byron ◽  
Keith S. Wilson ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Solution Structure ◽  
Low Resolution
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