Implication from the predicted docked interaction of sigma H and exploration of its interaction with RNA polymerase in Mycobacterium tuberculosis.

,Angshuman Bagchi,Sukhendu Mandal,Aayatti Mallick Gupta,Simanti Bhattacharya

doi:10.6026/97320630011296

, Angshuman Bagchi + Show 3 more

Open Access

https://doi.org/10.6026/97320630011296

Copy DOI

Journal: Bioinformation	Publication Date: Jun 30, 2015
Citations: 2	License type: cc-by

Affiliation: University of Kalyani, University of Calcutta

Abstract

M. tuberculosis is adapted to remain active in the extreme environmental condition due to the presence of atypical sigma factors commonly called extra cytoplasmic function (ECF) sigma factors. Among the 13 sigma factors of M. tuberculosis, 10 are regarded as the ECF sigma factor that exerts their attributes in various stress response. Therefore it is of interest to describe the structural prediction of one of the ECF sigma factors, sigma H (SigH), involved in oxidative and heat stress having interaction with the β׳ subunit of M. tuberculosis. RNA polymerase (Mtb-RNAP). The model of Mtb-SigH was build using the commercial package of Discovery Studio version 2.5 from Accelerys (San Diego, CA, USA) containing the inbuilt MODELER module and that of β׳ subunit of Mtb-RNAP using Phyre Server. Further, the protein models were docked using the fully automated web tool ClusPro (cluspro.bu.edu/login.php). Mtb-SigH is a triple helical structure having a putative DNA-binding site and the β׳ subunit of MtbRNAP consists of 18-beta sheets and 22 helices. The SigH-Mtb-RNAP β׳ interaction studies showed that Arg26, Gln19 andAsp18, residues of SigH protein are involved in binding with Arg137, Gln140, Arg152, Asn133 and Asp144 of β׳ subunit of Mtb-RNAP. The predicted model helps to explore the molecular mechanism in the control of gene regulation with a novel unique target for potential new generation inhibitor.

Highlights

Bacterial gene expression is primarily regulated at the level of transcription
In the last few years, after the publication of the M. tuberculosis whole genome sequence, the 13 sigma factors of M. tuberculosis have become an important subject of investigation of which 10 are regarded as the extra cytoplasmic function (ECF) sigma factors
ECF sigma factors play important role in bacterial pathogenecity and stress, among them sigma H (SigH) is involved in oxidative stress and heat stress [2, 3]

Summary

Introduction

Bacterial gene expression is primarily regulated at the level of transcription. Sigma factor plays a pivotal role in binding with the core RNAP and subsequently in promoter recognition [1]. Biochemical studies on bacterial RNA polymerase typically describe that domain 2 region of sigma factor binds with the β subunit of RNAP [1]. The present study delineates the structural understanding of Mtb-SigH and β subunit of Mtb-RNAP and thereby implicates the predicted interaction between them as one of the vital target for gene expression.

Results

Conclusion