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A previously unidentified σ factor and two accessory proteins regulate oxalate decarboxylase expression in Bacillus subtilis
Author(s) -
MacLellan Shawn R.,
Wecke Tina,
Helmann John D.
Publication year - 2008
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.1365-2958.2008.06331.x
Subject(s) - biology , sigma factor , operon , promoter , rna polymerase , bacillus subtilis , transcription (linguistics) , regulon , transcription factor , gene , general transcription factor , microbiology and biotechnology , rna polymerase ii , repressor , gene expression , rna , genetics , escherichia coli , linguistics , philosophy , bacteria
Summary We have investigated the function of a cell envelope stress‐inducible gene, yvrI , which encodes a 22.5 kDa protein that includes a predicted σ 70 region 4 domain, but lacks an apparent region 2 domain. YvrI interacts with RNA polymerase and overexpression of YvrI results in induction of OxdC, an oxalate decarboxylase maximally expressed under low‐pH conditions. We have used microarray‐based analyses to define the YvrI regulon. YvrI is required for the transcription of three operons ( oxdC‐yvrL , yvrJ and yvrI‐yvrHa ) each of which is preceded by a highly similar promoter sequence. Activation of these promoters requires both YvrI and the product of the second gene in the yvrI‐yvrHa operon, YvrHa. YvrI and YvrHa together allow recognition of the oxdC promoter, stimulate DNA melting and activate transcription by core RNA polymerase. Together, these results suggest that YvrI is a previously unrecognized σ factor in Bacillus subtilis and that the 9.5 kDa YvrHa protein acts as a required co‐activator of transcription. A yvrL deletion results in the upregulation of YvrI activity suggesting that YvrL is a negative regulator of YvrI‐dependent transcription, possibly functioning as an anti‐σ factor.