Shukla, Jinal and Gupta, Radhika and Thakur, Krishan Gopal and Gokhale, Rajesh and Gopal, B (2014) Structural basis for the redox sensitivity of the Mycobacterium tuberculosis SigK-RskA σ-anti-σ complex. Acta crystallographica. Section D, Biological crystallography, 70 (Pt 4). pp. 1026-36. ISSN 1399-0047
Full text not available from this repository. (Request a copy)Abstract
The host-pathogen interactions in Mycobacterium tuberculosis infection are significantly influenced by redox stimuli and alterations in the levels of secreted antigens. The extracytoplasmic function (ECF) σ factor σ(K) governs the transcription of the serodominant antigens MPT70 and MPT83. The cellular levels of σ(K) are regulated by the membrane-associated anti-σ(K) (RskA) that localizes σ(K) in an inactive complex. The crystal structure of M. tuberculosis σ(K) in complex with the cytosolic domain of RskA (RskAcyto) revealed a disulfide bridge in the -35 promoter-interaction region of σ(K). Biochemical experiments reveal that the redox potential of the disulfide-forming cysteines in σ(K) is consistent with its role as a sensor. The disulfide bond in σ(K) influences the stability of the σ(K)-RskAcyto complex but does not interfere with σ(K)-promoter DNA interactions. It is noted that these disulfide-forming cysteines are conserved across homologues, suggesting that this could be a general mechanism for redox-sensitive transcription regulation.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | transcription; redox sensitivity; secreted antigens; extracytoplasmic function [sigma] factors. |
| Subjects: | Q Science > QR Microbiology |
| Depositing User: | Dr. K.P.S.Sengar |
| Date Deposited: | 27 Jan 2015 09:47 |
| Last Modified: | 27 Jan 2015 09:47 |
| URI: | http://crdd.osdd.net/open/id/eprint/1532 |
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