Functional analysis of the pediocin operon of Pediococcus acidilactici PAC1.0: PedB is the immunity protein and PedD is the precursor processing enzyme

Abstract

The bacteriocin pediocin PA-1 operon of Pediococcus acidilactici PAC1.0 encompasses four genes: pedA, pedB, pedC and pedD. Transcription of the operon results in the formation of two overlapping transcripts, probably originating from a single promoter upstream of pedA. The major transcript comprises pedA, pedB, and pedC, while a minor transcript encompasses all of these genes and pedD. By deletion analysis and overexpression of pedB in Pediococcus pentosaceus we demonstrate that this gene encodes the pediocin PA-1 immunity protein. Prepediocin is active in Escherichia coli and when pedA was expressed concomitantly with pedD both the precursor and the mature form of pediocin were observed intracellularly. Extracellular pediocin was only detected if both pedC and pedD were present. The N-terminal domains of PedD and a subgroup of bacteriocin ABC-transporters are conserved. Expression of only this domain of PedD in cells producing prepediocin was sufficient for prepediocin processing. From these results we conclude that both PedC and PedD are essential for pediocin transport, and that PedD is capable of processing prepediocin.

Effect of Amino Acid Substitutions on the Activity of Carnobacteriocin B2

“…This result is in accord with the previous observation that the isolated immunity protein does not bind significantly to the parent bacteriocin CbnB2 in vitro (13). Genes for related immunity proteins have been found in other LAB bacteriocin-producing systems (17,(22)(23)(24)(25).…”

Double‐glycine‐type leader peptides direct secretion of bacteriocins by ABC transporters: colicin V secretion in Lactococcus lactis

“…The ABC transporters involved in transportation of substrates containing double-glycinetype leader peptides are also responsible for proteolytic cleavage of the precursor. In vitro and in vivo experiments showed that the proteolytic domain was located near the N-terminus (Hivarstein et al, 1995;Venema et al, 1995). Analysis of the possible topology of these ABC transporters indicated that the proteolytic domain is probably located in the cytoplasm (H5varstein et a/., 1995).…”

Structure-Function Analysis of Immunity Proteins of Pediocin-Like Bacteriocins: C-Terminal Parts of Immunity Proteins Are Involved in Specific Recognition of Cognate Bacteriocins

“…Genes encoding pediocin-like bacteriocins are cotranscribed with and/or in close vicinity to a gene encoding a cognate immunity protein which protects the bacteriocin producers from their own bacteriocin (2,10,19,27,28,37). Immunity genes that are not associated with bacteriocin genes have also been described (8).…”