Cloning and characterization of a novel cold-active endoglucanase establishing a new subfamily of glycosyl hydrolase family 5 from a psychrophilic deep-sea bacterium

• Published in: FEMS microbiology letters 2011-12, Vol.325 (1), p.71-76
• Main Authors: Yang, Jinying, Dang, Hongyue
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animal, plant and microbial ecology; Bacteria; Bacteriology; Biological and medical sciences; Carbohydrates; Carboxymethyl cellulose; Carboxymethylcellulose; Carboxymethylcellulose Sodium - metabolism; Cellulase; Cellulose; Cloning; Cloning, Molecular; Cluster Analysis; Cold Temperature; cold‐active; Deep sea; Deep sea environments; DNA, Bacterial - chemistry; DNA, Bacterial - genetics; Endoglucanase; Enzyme Stability; Fundamental and applied biological sciences. Psychology; Geologic Sediments - microbiology; Glucan 1,4-beta-Glucosidase - chemistry; Glucan 1,4-beta-Glucosidase - genetics; Glucan 1,4-beta-Glucosidase - metabolism; Glycosyl hydrolase; Hydrogen-Ion Concentration; Hydrolase; Microbial ecology; Microbiology; Miscellaneous; Molecular Sequence Data; Nitrophenylgalactosides - metabolism; Optimization; pH effects; Phylogeny; Pseudomonas; Pseudomonas - enzymology; Pseudomonas - genetics; Pseudomonas - isolation & purification; psychrophile; Sequence Analysis, DNA; Sequence Homology, Amino Acid; Substrate Specificity; Various environments (extraatmospheric space, air, water)
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1111/j.1574-6968.2011.02413.x

Abstract The gene of a novel endo-β-1,4-glucanase (named Cel5M) was isolated from the psychrophilic deep-sea bacteria Pseudomonas sp. MM15. The deduced protein sequence lacked the typical cellulase domain structures of the carbohydrate-binding module and the linker region. Cel5M showed relatively higher activity toward carboxymethyl cellulose, but much lower activity toward p-nitrophenyl-β-d-galactopyranoside and no activity toward avicel. Cel5M was identified as a cold-active cellulase with an optimal temperature of 30 °C and it was active within a narrow pH range with an optimum at pH 4.5. Phylogenetic analysis showed that Cel5M represented a new subfamily of the glycosyl hydrolase family 5, representing an opportunity for research into and applications of novel cold-active cellulases.