Character and nucleotide sequence of β-glucosidase gene from alcaligenes faecalis

Abstract

The recombinant plasmid pBAF 1200 which was constructed previously in our labpratpry contains -glucosidase gene isolated from Alcaligenes faecalis. This gene was analyzed for its nucleotide sequence and the $\beta$ -glucosidase produced by this gene was characterized in this research. In order to localize the $\beta$-glucosidase gene in pBAF 1200 more specifically, a subloning of the gene was performed. Both pBAF 1200 and pUC18 were digested with Hind III and ligated to form pGLU 283. From pGLU 283, a Pst I fragment was deleted to form pGLU 220 of 2.2 kb size. Through a series of restiction analysis, the $\beta$ -glucosidase gene was finally localized on a 2.2 kb fraction in pGLU 220. From experiments with E. coli transformants, it was confirmed that the A. faecalis $\beta$ -glucosidase gene expressed in E. coli using its own promoter. The $\beta$ -glucosidase production by the E. coli transformants was inhibited by the presence of glucose. The nucleotide sequence of the 2.2 kb DNA fragment which contains $\beta$ -glucosidase gene of A. faecalis origin is being progressed. From 1902 base pairs of analysis it was found that about 70\% of the nucleotide was of AT pairs.