The gal genes for the Leloir pathway of Lactobacillus casei 64H.

ABSTRACT: The gal genes from the chromosome of Lactobacillus casei 64H were cloned by complementation of the galK2 mutation of Escherichia coli HB101. The pUC19 derivative pKBL1 in one complementation-positive clone contained a 5.8-kb DNA HindIII fragment. Detailed studies with other E. coli K-12 strains indicated that plasmid pKBL1 contains the genes coding for a galactokinase (GalK), a galactose 1-phosphate-uridyltransferase (GalT), and a UDP-galactose 4-epimerase (GalE). In vitro assays demonstrated that the three enzymatic activities are expressed from pKBL1. Sequence analysis revealed that pKBL1 contained two additional genes, one coding for a repressor protein of the LacI-GalR-family and the other coding for an aldose 1-epimerase (mutarotase). The gene order of the L. casei gal operon is galKE

SUBMITTER: Bettenbrock K 

PROVIDER: S-EPMC106272 | biostudies-literature | 1998 Jun

REPOSITORIES: biostudies-literature