Cloning, sequence analysis, and characterization of the genes involved in isoprimeverose metabolism in Lactobacillus pentosus.

ABSTRACT: Two genes, xylP and xylQ, from the xylose regulon of Lactobacillus pentosus were cloned and sequenced. Together with the repressor gene of the regulon, xylR, the xylPQ genes form an operon which is inducible by xylose and which is transcribed from a promoter located 145 bp upstream of xylP. A putative xylR binding site (xylO) and a cre-like element, mediating CcpA-dependent catabolite repression, were found in the promoter region. L. pentosus mutants in which both xylP and xylQ (LPE1) or only xylQ (LPE2) was inactivated retained the ability to ferment xylose but were impaired in their ability to ferment isoprimeverose (alpha-D-xylopyranosyl-(1,6)-D-glucopyranose). Disruption of xylQ resulted specifically in the loss of a membrane-associated alpha-xylosidase activity when LPE1 or LPE2 cells

SUBMITTER: Chaillou S 

PROVIDER: S-EPMC107170 | biostudies-literature | 1998 May

REPOSITORIES: biostudies-literature