The DNA Sequence of a Novel B-Galactosidase Gene from Lactobacillus Casei ATCC 393
MetadataShow full item record
The majority of the DNA sequence of a novel B-galactosidase from Lactobacillus casei ATCC393 was determined and compared with those of other B-galactosidase enzymes. The gene had been found on pLZ15, and was subcloned as a 5.2 kilobase subfragment in Escherichia coli. The subclone was found to contain the B-galactosidase gene, and was then subcloned again as three different restriction fragments, using pUC18 as the vector. These plasmids were isolated and used to run the sequencing reactions. Dideoxynucleotide chain terminating reactions (Sanger et al., 1977) were used to complete the sequence analysis. Although not yet completely characterized, the sequence shows a high degree of homology with the B-galactosidase sequence from Lactobacillus bulgaricus. The promoter region has not been found, but a putative terminator has been identified.