Cloning and nucleotide sequence of bgl A gene from Erwinia herbicola and expression of ß-glucosidase activity in Escherichia coli.

Genomic DNA fragments encoding β-glucosidase activity from the wild-type strain WD4 of Erwinia herbicola were cloned into Escherichia coli. Two clones containing a common fragment encoded a polypeptide of 58 000 Da. Cloned β- glucosidase, expressed in E. coli, showed activity against natural β- glucoside sugars except for cellobiose. An open reading frame of 1442 bp termed bglA was identified by nucleotide sequencing and it coded for a protein of 480 amino acids (M(r) 53 896) which showed significant homology with β-glucosidases from glycosyl hydrolase family.