title: Cloning and characterization of the bgxA gene from Erwinia chrysanthemi D1 which encodes a beta-glucosidase/xylosidase enzyme.
abstract: A beta-glucosidase/xylosidase gene from Erwinia chrysanthemi strain D1 was cloned and sequenced. This gene, named bgxA, encodes a ca. 71 kDa protein product which, following removal of the leader peptide, resulted in a ca. 69 kDa mature protein that accumulated in the periplasmic space of E. chrysanthemi strain D1 and Escherichia coli cells expressing the cloned gene. The protein exhibited both beta-glucosidase and beta-xylosidase activities but gave no detectable activity on xylan or carboxymethyl cellulose. The enzyme was classified as a type 3 glycosyl hydrolase, but was unusual in having a truncated B region at the carboxyl-terminus. Several E. chrysanthemi strains isolated from corn produced the glucosidase/xylosidase activity but not those isolated from dicot plants. However, bgxA marker exchange mutants of strain D1 were not detectably altered in virulence on corn leaves.
authors.affiliation: Department of Plant Pathology, University of California, Riverside 92521.
authors.forename: S
authors.initials: S
authors.lastname: Vroemen
authors.forename: J
authors.initials: J
authors.lastname: Heldens
authors.forename: C
authors.initials: C
authors.lastname: Boyd
authors.forename: B
authors.initials: B
authors.lastname: Henrissat
authors.forename: N T
authors.initials: NT
authors.lastname: Keen
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D001483:Base Sequence; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D016974:Dickeya chrysanthemi / Q000201:enzymology / Q000235:genetics* / Q000472:pathogenicity; D005798:Genes, Bacterial / Q000235:genetics*; D005822:Genetic Vectors; D008969:Molecular Sequence Data; D010957:Plasmids; D017384:Sequence Deletion; D014774:Virulence / Q000235:genetics; D014995:Xylosidases / Q000235:genetics*; D003313:Zea mays / Q000382:microbiology; D001617:beta-Glucosidase / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D014995:Xylosidases; D001617:beta-Glucosidase; C092512:BgxA protein, Erwinia chrysanthemi