title: Molecular cloning and characterization of an endogenous digestive β-glucosidase from the midgut of the fungus-growing termite Macrotermes barneyi.
abstract: β-glucosidase from the midgut of the fungus-growing termite Macrotermes barneyi was first cloned and characterized to gain a better understanding of cellulolytic systems in fungus-growing termites. β-glucosidase activity was proven to present primarily in the midgut of M. barneyi and two β-glucosidases were partially purified from the midgut. Based on the N-terminus sequence of one of the β-glucosidases, a full-length cDNA fragment of 1708 bp was obtained. This sequence encodes a 493 amino acid protein belonging to glycoside hydrolase family 1. Quantitative real-time PCR analysis proved that the β-glucosidase gene was primarily expressed in the midgut. β-glucosidase was expressed heterologously and biochemically characterized. Results indicate that β-glucosidase is an endogenous, midgut-origin termite digestive enzyme. It may have applications in understanding the mechanism of lignocellulose degradation in fungus-growing termites.
authors.affiliation: State Key Laboratory of Microbial Technology, Shandong University, Jinan, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Wu
authors.forename: S
authors.initials: S
authors.lastname: Chi
authors.forename: C
authors.initials: C
authors.lastname: Yun
authors.forename: Y
authors.initials: Y
authors.lastname: Shen
authors.forename: G
authors.initials: G
authors.lastname: Tokuda
authors.forename: J
authors.initials: J
authors.lastname: Ni
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004926:Escherichia coli; D041981:Gastrointestinal Tract / Q000201:enzymology / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D020049:Isoptera / Q000201:enzymology*; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000378:metabolism; D012469:Salivary Glands / Q000201:enzymology; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein; D013379:Substrate Specificity; D013696:Temperature; D001617:beta-Glucosidase / Q000235:genetics / Q000378:metabolism*
chemical_list: D019476:Insect Proteins; D012333:RNA, Messenger; D001617:beta-Glucosidase