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Genome‐wide responses to carbonyl electrophiles in Bacillus subtilis : control of the thiol‐dependent formaldehyde dehydrogenase AdhA and cysteine proteinase YraA by the MerR‐family regulator YraB (AdhR)
Author(s) -
Huyen Nguyen Thi Thu,
Eiamphungporn Warawan,
Mäder Ulrike,
Liebeke Manuel,
Lalk Michael,
Hecker Michael,
Helmann John D.,
Antelmann Haike
Publication year - 2009
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2008.06568.x
Subject(s) - bacillus subtilis , operon , biochemistry , cysteine , regulon , formaldehyde dehydrogenase , biology , thiol , transcription factor , enzyme , gene , glutathione , escherichia coli , genetics , bacteria
Summary Quinones and α,β‐unsaturated carbonyls are naturally occurring electrophiles that target cysteine residues via thiol‐(S)‐alkylation. We analysed the global expression profile of Bacillus subtilis to the toxic carbonyls methylglyoxal (MG) and formaldehyde (FA). Both carbonyl compounds cause a stress response characteristic for thiol‐reactive electrophiles as revealed by the induction of the Spx, CtsR, CymR, PerR, ArsR, CzrA, CsoR and SigmaD regulons. MG and FA triggered also a SOS response which indicates DNA damage. Protection against FA is mediated by both the hxlAB operon, encoding the ribulose monophosphate pathway for FA fixation, and a thiol‐dependent formaldehyde dehydrogenase (AdhA) and DJ‐1/PfpI‐family cysteine proteinase (YraA). The adhA–yraA operon and the yraC gene, encoding a γ‐carboxymuconolactone decarboxylase, are positively regulated by the MerR‐family regulator, YraB(AdhR). AdhR binds specifically to its target promoters which contain a 7‐4‐7 inverted repeat (CTTAAAG‐N4‐CTTTAAG) between the −35 and −10 elements. Activation of adhA–yraA transcription by AdhR requires the conserved Cys52 residue in vivo . We speculate that AdhR is redox‐regulated via thiol‐(S)‐alkylation by aldehydes and that AdhA and YraA are specifically involved in reduction of aldehydes and degradation or repair of damaged thiol‐containing proteins respectively.