5hs8
Crystal structure of the diamide-treated YodB from B. subtilis
Structural highlights
FunctionYODB_BACSU Negatively regulates yodC and azoR1 which may contribute to the degradation of aromatic compounds. Probably positively regulates the catechol-specific transcription of mhqNOP, mhqED, and mhqA.[1] Publication Abstract from PubMedFor bacteria, cysteine thiol groups in proteins are commonly used as thiol-based switches for redox sensing to activate specific detoxification pathways and restore the redox balance. Among the known thiol-based regulatory systems, the MarR/DUF24 family regulators have been reported to sense and respond to reactive electrophilic species, including diamide, quinones, and aldehydes, with high specificity. Here, we report that the prototypical regulator YodB of the MarR/DUF24 family from Bacillus subtilis uses two distinct pathways to regulate transcription in response to two reactive electrophilic species (diamide or methyl-p-benzoquinone), as revealed by X-ray crystallography, NMR spectroscopy, and biochemical experiments. Diamide induces structural changes in the YodB dimer by promoting the formation of disulfide bonds, whereas methyl-p-benzoquinone allows the YodB dimer to be dissociated from DNA, with little effect on the YodB dimer. The results indicate that B. subtilis may discriminate toxic quinones, such as methyl-p-benzoquinone, from diamide to efficiently manage multiple oxidative signals. These results also provide evidence that different thiol-reactive compounds induce dissimilar conformational changes in the regulator to trigger the separate regulation of target DNA. This specific control of YodB is dependent upon the type of thiol-reactive compound present, is linked to its direct transcriptional activity, and is important for the survival of B. subtilis This study of B. subtilis YodB also provides a structural basis for the relationship that exists between the ligand-induced conformational changes adopted by the protein and its functional switch. Two distinct mechanisms of transcriptional regulation by the redox sensor YodB.,Lee SJ, Lee IG, Lee KY, Kim DG, Eun HJ, Yoon HJ, Chae S, Song SH, Kang SO, Seo MD, Kim HS, Park SJ, Lee BJ Proc Natl Acad Sci U S A. 2016 Aug 30;113(35):E5202-11. doi:, 10.1073/pnas.1604427113. Epub 2016 Aug 16. PMID:27531959[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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