title: Comparative amino acid sequence analysis of Thermotoga maritima beta-glucosidase (BglA) deduced from the nucleotide sequence of the gene indicates distant relationship between beta-glucosidases of the BGA family and other families of beta-1,4-glycosyl hydrolases.
abstract: The primary structure of the bglA gene region encoding a beta-glucosidase of Thermotoga maritima strain MSB8 was determined. The bglA gene has the potential to code for a polypeptide of 446 amino acids with a predicted molecular mass of 51,545 Da. The T. maritima beta-glucosidase (BglA) was overexpressed in E. coli at a level comprising approximately 15-20% of soluble cellular protein. Based on its amino acid sequence, as deduced from the nucleotide sequence of the gene, BglA can be classified as a broad-specificity beta-glucosidase and as a member of the beta-glucosidase family BGA, in agreement with the results of enzymatic characterization of the recombinant protein. Comparative sequence analysis revealed distant amino acid sequence similarities between BGA family beta-glucosidases, a beta-xylosidase, beta-1,4-glycanases of the enzyme family F (mostly xylanases), and other families of beta-1,4-glycosyl hydrolases. This result indicates that BGA beta-glucosidases may comprise one enzyme family within a large 'enzyme order' of retaining beta-glycosyl hydrolases, and that the members of these enzyme groups may be inter-related at the level of active site architecture and perhaps even on the level of overall three-dimensional fold.
authors.affiliation: Lehrstuhl für Mikrobiologie, Technische Universität München, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Liebl
authors.forename: J
authors.initials: J
authors.lastname: Gabelsberger
authors.forename: K H
authors.initials: KH
authors.lastname: Schleifer
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry; D001482:Base Composition; D001483:Base Sequence; D003001:Cloning, Molecular; D016384:Consensus Sequence; D017124:Conserved Sequence; D004926:Escherichia coli / Q000201:enzymology; D005966:Glucuronidase / Q000737:chemistry / Q000145:classification; D006026:Glycoside Hydrolases / Q000737:chemistry* / Q000145:classification*; D006089:Gram-Negative Anaerobic Bacteria / Q000201:enzymology*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D011487:Protein Conformation; D011993:Recombinant Fusion Proteins; D016415:Sequence Alignment; D013379:Substrate Specificity; D014995:Xylosidases / Q000737:chemistry / Q000145:classification; D001617:beta-Glucosidase / Q000737:chemistry* / Q000145:classification / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D011993:Recombinant Fusion Proteins; D006026:Glycoside Hydrolases; D014995:Xylosidases; C020668:glycanase; D001617:beta-Glucosidase; D005966:Glucuronidase