title: Cloning, expression and characterization of a novel GH5 exo/endoglucanase of Thermobiﬁda halotolerans YIM 90462(T) by genome mining.
abstract: The 1389-bp thcel5A gene, which encodes a family 5 of glycoside hydrolases (GH5), was screened from the draft genome of Thermobiﬁda halotolerans YIM 90462(T). ThCel5A was most similar (77% identity) to a GH5 endoglucanase from Thermobiﬁda fusca YX, followed by cellulases from Nocardiopsis dassonvillei subsp. dassonvillei DSM 43111, Nocardiopsis alba ATCC BAA-2165, and Kribbella flavida DSM 17836. The deduced amino acid sequence of ThCel5A, which consisted of 462 amino acid residues, encompassed a family 2 cellulose-binding module and a GH5 catalytic domain. Notably, ThCel5A hydrolysed soluble as well as insoluble cellulose substrates. The enzymatic hydrolysis assay showed that the activity of recombinant ThCel5A was optimized at pH 8.0 and 50°C. Moreover, it retained hydrolytic activity in the presence of various metal ions and >90% activity within the range of pH 8.0-9.0 after 30 min at 50°C. These results suggested that this enzyme has considerable potential in industrial applications.
authors.affiliation: School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan Institute of Microbiology, Yunnan University, Kunming 650091, PR China.
authors.forename: Xiao-Mei
authors.initials: XM
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan Institute of Microbiology, Yunnan University, Kunming 650091, PR China.
authors.forename: Yi-Rui
authors.initials: YR
authors.lastname: Yin
authors.affiliation: College of Ecology and Evolution, Sun Yat-Sen University, Guangzhou 510275, PR China; Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan Institute of Microbiology, Yunnan University, Kunming 650091, PR China. Electronic address: liwenjun3@mail.sysu.edu.cn.
authors.forename: Wen-Jun
authors.initials: WJ
authors.lastname: Li
mesh_terms: D000192:Actinomycetales / Q000201:enzymology* / Q000235:genetics*; D001709:Biotechnology; D020134:Catalytic Domain; D002480:Cellulase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D002482:Cellulose / Q000378:metabolism; D003001:Cloning, Molecular; D016680:Genome, Bacterial / Q000235:genetics*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D012995:Solubility; D013379:Substrate Specificity; D013696:Temperature; D013997:Time Factors
chemical_list: D002482:Cellulose; D002480:Cellulase
keywords: GH5 exo/endoglucanase; Genome; Industrial applications; Thermobiﬁda halotolerans YIM 90462(T)