A CONSERVED SEQUENCE IN TRANSFER-RNA AND RIBOSOMAL-RNA PROMOTERS OF LACTOCOCCUS-LACTIS

A tRNA operon (trnA) from Lactococcus lactis consisting of seven tRNA genes and a 5S rRNA gene was cloned and sequenced. Promoter-fusion of the trnA promoter to a promoter-less beta-galactosidase gene of Leucon ostoc mesenteroides resulted in high levels of beta-galactosidase acti vity in L. lactis. Searching for sequences with similarity to the sequ ence of the promoter region revealed a consensus sequence of promoters preceeding rRNA operons and tRNA operons from Lactococcus species inc luding a not previously described conserved sequence (AGTT).