Journal Article


R P Ross
C Hill
T O'Keeffe
O McAuliffe



repressor proteins lacticin 481 genetics molecular sequence data genes bacterial transcription genetic anti bacterial agents promoter regions genetic metabolism base sequence lactococcus lactis multigene family bacterial proteins bacteriocins immunology gene expression regulation bacterial

Regulation of immunity to the two-component lantibiotic, lacticin 3147, by the transcriptional repressor LtnR. (2001)

Abstract Lacticin 3147 is a membrane-active, two-component lantibiotic produced by Lactococcus lactis ssp. lactis DPC3147. In this study, the promoters of the lacticin 3147 gene cluster were mapped to the intergenic region between ltnR and ltnA1 (the genes encoding the regulatory protein LtnR and the first structural gene, LtnA1), and Northern analyses revealed that the biosynthetic and immunity genes are divergently transcribed in two operons, ltnA1A2M1TM2D and ltnRIFE respectively. Although the promoter controlling biosynthesis (Pbac) appears to be constitutive, characterization of a downstream beta-galactosidase (beta-gal) fusion beyond an intragenic stem-loop structure in ltnM1 confirmed that this putative transcriptional attenuator allows limited readthrough to the downstream biosynthetic genes, thus maintaining the correct stoichiometry between structural peptides and biosynthetic machinery. The promoter of the ltnRIFE operon (Pimm) was shown to be regulated by the transcriptional repressor LtnR. A mutant with a truncated ltnR gene exhibited a hyperimmune phenotype, whereas overexpression of ltnR resulted in cells with increased sensitivity to lacticin 3147. Gel mobility shift analysis indicated that LtnR binds to the Pimm promoter region, and fusion of this promoter to the beta-gal gene of pAK80 revealed that expression from Pimm is significantly reduced in the presence of LtnR. Thus, we have demonstrated that lacticin 3147 uses a regulatory mechanism not previously identified in lantibiotic systems.
Collections Ireland -> University College Cork -> PubMed

Full list of authors on original publication

R P Ross, C Hill, T O'Keeffe, O McAuliffe

Experts in our system

R Paul Ross
Total Publications: 441
Colin Hill
University College Cork
Total Publications: 351
Olivia McAuliffe
Total Publications: 64