Molecular cloning of rhodanese gene from soil metagenome of cold desert of North-West Himalayas: sequence and structural features of the rhodanese enzyme.
Rhodanese is a multifunctional, sulfur transferase that catalyzes the detoxification of cyanide by sulphuration in a double displacement (ping pong) mechanistic reaction. In the present study, small-insert metagenomic library from soil sample collected from Ladakh (3,000-3,600 m.a.s.l) in northwestern Himalayas, India was constructed. Function-driven screening of ~8,500 colonies led to the isolation of one esterase-positive clone (clone-est) harboring 2.43 kb insert. Sequence analysis of the insert identified two ORF's, phosM encoding phosphoesterase and rodM encoding rhodanese. The 800 bp rodM gene encoded a polypeptide of 227 amino acids (RodM). The RodM showed maximum homology with the rhodanese-like protein from Cyanobacterium synechococcus species with a score identity of only 51 %. Putative 3D structure of RodM developed by homology modeling resembles to homodimeric protein of SUD sulfur transferase of Wolinella succinogenes with properly structured active-site cysteine (Cys) residue. Rhodanese has been reported from few culturable microorganisms.
Microbial Biotechnology Division, CSIR-Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu Tawi, 180 001, India.
Archana
A
Bhat
Microbial Biotechnology Division, CSIR-Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu Tawi, 180 001, India.
Syed
S
Riyaz-Ul-Hassan
Department of Biosciences and Biotechnology, Banasthali University, Jaipur, India.
Nidhi
N
Srivastava
Microbial Biotechnology Division, CSIR-Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu Tawi, 180 001, India. sarojini.johri@gmail.com.
Sarojini
S
Johri
Cloning; Cyanide; Homology; Metagenomic; Sulfurtransferase