Posttranslational conversion of L-serines to D-alanines is vital for optimal production and activity of the lantibiotic lacticin 3147.

ABSTRACT: As a general rule, ribosomally synthesized polypeptides contain amino acids only in the L-isoform in an order dictated by the coding DNA/RNA. Two of a total of only four examples of L to D conversions in prokaryotic systems occur in posttranslationally modified antimicrobial peptides called lantibiotics. In both examples (lactocin S and lacticin 3147), ribosomally encoded L-serines are enzymatically converted to D-alanines, giving rise to an apparent mistranslation of serine codons to alanine residues. It has been suggested that this conversion results from a two-step reaction initiated by a lantibiotic synthetase converting the gene-encoded L-serine to dehydroalanine (dha). By using lacticin 3147 as a model system, we report the identification of an enzyme, LtnJ, that is responsible for t

SUBMITTER: Cotter PD 

PROVIDER: S-EPMC1317978 | biostudies-literature | 2005 Dec

REPOSITORIES: biostudies-literature