title: Molecular characterization of SCO0765 as a cellotriose releasing endo-β-1,4-cellulase from Streptomyces coelicolor A(3).
abstract: The sco0765 gene was annotated as a glycosyl hydrolase family 5 endoglucanase from the genomic sequence of Streptomyces coelicolor A3(2) and consisted of 2,241 bp encoding a polypeptide of 747 amino acids (molecular weight of 80.5 kDa) with a 29-amino acid signal peptide for secretion. The SCO0765 recombinant protein was heterogeneously over-expressed in Streptomyces lividans TK24 under the control of a strong ermE* promoter. The purified SCO0765 protein showed the expected molecular weight of the mature form (718 aa, 77.6 kDa) on sodium dodecyl sulfate-polyacryl amide gel electrophoresis. SCO0765 showed high activity toward β-glucan and carboxymethyl cellulose (CMC) and negligible activity to Avicel, xylan, and xyloglucan. The SCO0765 cellulase had a maximum activity at pH 6.0 and 40°C toward CMC and at pH 9.0 and 50-60°C toward β-glucan. Thin layer chromatography of the hydrolyzed products of CMC and β-glucan by SCO0765 gave cellotriose as the major product and cellotetraose, cellopentaose, and longer oligosaccharides as the minor products. These results clearly demonstrate that SCO0765 is an endo-β-1,4-cellulase, hydrolyzing the β-1,4 glycosidic bond of cellulose into cellotriose.
authors: Korea University Business School, Korea University, Seoul, 02841, Republic of Korea.
authors: Joo-Bin
authors: JB
authors: Hong
authors: Department of Bioscience and Bioinformatics, Myongji University, Yongin, 17058, Republic of Korea.
authors: Vijayalakshmi
authors: V
authors: Dhakshnamoorthy
authors: Department of Bioscience and Bioinformatics, Myongji University, Yongin, 17058, Republic of Korea. crlee@mju.ac.kr.
authors: Chang-Ro
authors: CR
authors: Lee
mesh_terms: D002480:Cellulase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002482:Cellulose / Q000031:analogs & derivatives* / Q000378:metabolism; D004795:Enzyme Stability; D005656:Fungal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008970:Molecular Weight; D048372:Streptomyces coelicolor / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity; D013780:Tetroses / Q000378:metabolism*; D047071:beta-Glucans / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D013780:Tetroses; D047071:beta-Glucans; C048468:cellotetraose; D002482:Cellulose; D002480:Cellulase
keywords: GH 5 family; SCO0765; Streptomyces coelicolor; cellotriose; endo-β-1,4-cellulase