Metagenomic approaches are recently used for searching novel open reading frames （ORFs） coding enzymes employed in pharmaceutical, rood industries, etc. In this study, a metagenornic library was constructed from Chu...Metagenomic approaches are recently used for searching novel open reading frames （ORFs） coding enzymes employed in pharmaceutical, rood industries, etc. In this study, a metagenornic library was constructed from Chumathang hotspring sediment DNA. The library consisted of approximately 9,000 clones and was screened for protease activity. A clone exhibiting protease activity was identified and named CHprol. Sequencing of CHprol revealed that the ORF encoded a functional protein of 363 amino acids belonging to peptidase S8-S53 superfamily. CHprol shared 41% sequence similarity with a reported protease （subtilase family） and 35 % structural similarity with the crystal structure of Pro-Tk sps. of Thermococcus kodarkaenasis. In silico modeling the 3D structure of CHprol showed that it has two beta sheets, 10 alpha helices and 11 strands. Catalytic triad prediction implied CHprol to be a serine protease. The optimum temperature and pH of the purified protease were found to be 80 ℃ and 11.0, respectively. The enzyme was active at 5 % concentration of hydrogen peroxide and retained 60 % of activity at 10 % concentration. The thermotolerant, alkalophilic and oxidant stable properties of the protease make it a potential can- didate for biotechnological applications.展开更多
基金supported by Council of Scientific and Industrial Research(CSIR)New Delhi,Government of India(37(1545)/12/EMR-II)entitled‘‘Exploring Microbial DiversityMining Novel Hydrolases from Brackish Water Lakes of Ladakh Region by Metagenomic Approach.’’
文摘Metagenomic approaches are recently used for searching novel open reading frames （ORFs） coding enzymes employed in pharmaceutical, rood industries, etc. In this study, a metagenornic library was constructed from Chumathang hotspring sediment DNA. The library consisted of approximately 9,000 clones and was screened for protease activity. A clone exhibiting protease activity was identified and named CHprol. Sequencing of CHprol revealed that the ORF encoded a functional protein of 363 amino acids belonging to peptidase S8-S53 superfamily. CHprol shared 41% sequence similarity with a reported protease （subtilase family） and 35 % structural similarity with the crystal structure of Pro-Tk sps. of Thermococcus kodarkaenasis. In silico modeling the 3D structure of CHprol showed that it has two beta sheets, 10 alpha helices and 11 strands. Catalytic triad prediction implied CHprol to be a serine protease. The optimum temperature and pH of the purified protease were found to be 80 ℃ and 11.0, respectively. The enzyme was active at 5 % concentration of hydrogen peroxide and retained 60 % of activity at 10 % concentration. The thermotolerant, alkalophilic and oxidant stable properties of the protease make it a potential can- didate for biotechnological applications.
