title: Cloning, expression and characterization of an alkaline thermostable GH9 endoglucanase from Thermobifida halotolerans YIM 90462 T.
abstract: The endoglucanase gene, thcel9A, from Thermobifida halotolerans YIM 90462(T) was cloned and expressed in Escherichia coli BL 21(DE). The 2895-bp full-length gene encodes a 964-residue polypeptide (Thcel9A) containing a catalytic domain belonging to glycosyl hydrolases (GH) family 9. Phylogenetic analysis indicated that Thcel9A is closely related to Cel9A of Thermobifidafusca YX. Thcel9A was purified from the culture supernatant by Ni(2+)-affinity chromatography and the purified enzyme exhibited optimal activity at 55°C and pH 8.0. Substrate specificity assays showed that it not only had CMCase activity, but also hydrolase activity on microcrystalline cellulose and filter paper. These properties suggested that Thcel9A is a classical GH9 group A endoglucanase.
authors: Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education and Laboratory for Conservation and Utilization of Bio-Resources, Yunnan Institute of Microbiology, Yunnan University, Kunming 650091, PR China.
authors: Feng
authors: F
authors: Zhang
authors: Jiu-Jiu
authors: JJ
authors: Chen
authors: Wan-Zeng
authors: WZ
authors: Ren
authors: Guo-Xing
authors: GX
authors: Nie
authors: Hong
authors: H
authors: Ming
authors: Shu-Kun
authors: SK
authors: Tang
authors: Wen-Jun
authors: WJ
authors: Li
mesh_terms: D000192:Actinomycetales / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics*; D000468:Alkalies / Q000494:pharmacology*; D002480:Cellulase / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability / Q000187:drug effects; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D007700:Kinetics; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000378:metabolism; D013379:Substrate Specificity / Q000187:drug effects; D013696:Temperature
chemical_list: D000468:Alkalies; D011994:Recombinant Proteins; D002480:Cellulase