6onu

Structural highlights

Function

[WHIB1_MYCTU] Acts as a transcriptional repressor, inhibiting expression in vitro. Probably redox-responsive. The apo- but not holo-form binds to its own promoter as well as that of groEL2. Oxidized apo-form and nitrosylated holo-form also bind DNA. The apo-form has been shown to act as a protein disulfide reductase (PubMed:17157031) (PubMed:19016840), but also not to act as a protein disulfide reductase (PubMed:20929442).^{[1] [2] [3] [4]} [SIGA_MYCTU] Sigma factors are initiation factors that promote the attachment of RNA polymerase to specific initiation sites and are then released. This sigma factor is the primary sigma factor during exponential growth (Probable).^{[5] [6] [7]}

References

1. ↑ Garg SK, Suhail Alam M, Soni V, Radha Kishan KV, Agrawal P. Characterization of Mycobacterium tuberculosis WhiB1/Rv3219 as a protein disulfide reductase. Protein Expr Purif. 2007 Apr;52(2):422-32. doi: 10.1016/j.pep.2006.10.015. Epub, 2006 Nov 10. PMID:17157031 doi:http://dx.doi.org/10.1016/j.pep.2006.10.015
2. ↑ Alam MS, Garg SK, Agrawal P. Studies on structural and functional divergence among seven WhiB proteins of Mycobacterium tuberculosis H37Rv. FEBS J. 2009 Jan;276(1):76-93. doi: 10.1111/j.1742-4658.2008.06755.x. PMID:19016840 doi:http://dx.doi.org/10.1111/j.1742-4658.2008.06755.x
3. ↑ Smith LJ, Stapleton MR, Fullstone GJ, Crack JC, Thomson AJ, Le Brun NE, Hunt DM, Harvey E, Adinolfi S, Buxton RS, Green J. Mycobacterium tuberculosis WhiB1 is an essential DNA-binding protein with a nitric oxide-sensitive iron-sulfur cluster. Biochem J. 2010 Dec 15;432(3):417-27. PMID:20929442
4. ↑ Stapleton MR, Smith LJ, Hunt DM, Buxton RS, Green J. Mycobacterium tuberculosis WhiB1 represses transcription of the essential chaperonin GroEL2. Tuberculosis (Edinb). 2012 Jul;92(4):328-32. doi: 10.1016/j.tube.2012.03.001., Epub 2012 Mar 29. PMID:22464736 doi:http://dx.doi.org/10.1016/j.tube.2012.03.001
5. ↑ Beaucher J, Rodrigue S, Jacques PE, Smith I, Brzezinski R, Gaudreau L. Novel Mycobacterium tuberculosis anti-sigma factor antagonists control sigmaF activity by distinct mechanisms. Mol Microbiol. 2002 Sep;45(6):1527-40. PMID:12354223
6. ↑ Hartkoorn RC, Sala C, Magnet SJ, Chen JM, Pojer F, Cole ST. Sigma factor F does not prevent rifampin inhibition of RNA polymerase or cause rifampin tolerance in Mycobacterium tuberculosis. J Bacteriol. 2010 Oct;192(20):5472-9. doi: 10.1128/JB.00687-10. Epub 2010 Aug 20. PMID:20729364 doi:http://dx.doi.org/10.1128/JB.00687-10
7. ↑ Hu Y, Morichaud Z, Chen S, Leonetti JP, Brodolin K. Mycobacterium tuberculosis RbpA protein is a new type of transcriptional activator that stabilizes the sigma A-containing RNA polymerase holoenzyme. Nucleic Acids Res. 2012 Aug;40(14):6547-57. doi: 10.1093/nar/gks346. Epub 2012, May 8. PMID:22570422 doi:http://dx.doi.org/10.1093/nar/gks346