The Protein Journal

, Volume 30, Issue 2, pp 91–101

Validation of Arsenic Resistance in Bacillus cereus Strain AG27 by Comparative Protein Modeling of arsC Gene Product

  • Sourabh Jain
  • Bhoomika Saluja
  • Abhishek Gupta
  • Soma S. Marla
  • Reeta Goel
Article

DOI: 10.1007/s10930-011-9305-5

Cite this article as:
Jain, S., Saluja, B., Gupta, A. et al. Protein J (2011) 30: 91. doi:10.1007/s10930-011-9305-5
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Abstract

The ars gene system provides arsenic resistance to a variety of microorganisms and can be chromosomal or plasmid-borne. The arsC gene, which codes for an arsenate reductase is essential for arsenate resistance and transforms arsenate into arsenite, which is extruded from the cell. Therefore, arsC gene from Bacilluscereus strain AG27 isolated from soil was amplified, cloned and sequenced. The strain exhibited a minimum inhibitory concentration of 40 and 35 mM to sodium arsenate and sodium arsenite, respectively. Homology of the sequence, when compared with available database using BLASTn search showed that 300 bp amplicons obtained possess partial arsC gene sequence which codes for arsenate reductase, an enzyme involved in the reduction of arsenate to arsenite which is then effluxed out of the cell, thereby indicating the presence of efflux mechanism of resistance in strain. The efflux mechanism was further confirmed by atomic absorption spectroscopy and scanning electron microscopy studies. Moreover, three dimensional structure of modeled arsC from Bacillus cereus strain shares significant structural similarity with arsenate reductase protein of B.subtilis, consisting of, highly similar overall fold with single α/β domain containing a central four stranded, parallel, open-twisted β-sheet flanked by α-helices on both sides. The structure harbors the arsenic binding motif AB loop or P-loop that is highly conserved in arsenate reductase family.

Keywords

arsCBacillus cereusHomology modeling3D structure

Abbreviations

arsC

Arsenate reductase C

3D structure

Three dimensional structure

As

Arsenic

arsB

Arsenate reductase B

MIC

Minimum inhibitory concentration

16S rDNA

16S Ribosomal DNA

NCBI

National centre of biotechnological information

BLASTp

Basic local alignment search tool protein

PDB

Protein database

ExPasy

Expert protein analysis system

SIB

Swiss institute of bionformatics

SEM

Scanning electron microscopy

PMDB

Protein model database

Cys

Cysteine

Thr

Threonine

Ser

Serine

His

Histidine

Asp

Aspartate

Arg

Arginine

Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  • Sourabh Jain
    • 1
  • Bhoomika Saluja
    • 1
  • Abhishek Gupta
    • 1
  • Soma S. Marla
    • 2
  • Reeta Goel
    • 1
  1. 1.Department of MicrobiologyG.B. Pant University of Agriculture and TechnologyPantnagarIndia
  2. 2.DNA Fingerprinting DivisionNational Bureau of Plant Genetic ResourcesNew DelhiIndia