Two Different Lantibiotic-Like Peptides Originate from the Ericin Gene Cluster of Bacillus subtilis A1/3

Abstract

A lantibiotic gene cluster was identified inLantibiotics are amphiphilic peptide antibiotics of bacterial origin and are nearly exclusively produced by gram-positive bacteria. They contain unusual constituents like nonproteinogenic didehydroamino acids and lanthionines (49; for reviews, see references 16, 30, 47, and 51). Out of the about 26 known lantibiotics, the nisins (A and Z) of Lactococcus lactis cheese starter organisms (6, 15) are the best-studied members which are also of commercial value (5,14,21,31,33,41). Subtilin was the first lantibiotic isolated from Bacillus subtilis ATCC 6633 (22; for review, see reference 16). A variant of subtilin (subtilin B) was found to have reduced antibiotic activity due to posttranslational succinylation of the amino group of the N-terminal tryptophan residue (7). Sublancin from B. subtilis 168 is quite different and contains a single lanthionine linkage and two disulfide bridges (43). A relative small lantibiotic, mersacidin of Bacillus sp., shows unusual properties with respect to bridging, amphiphilic character, and C-terminal modification (30). Lantibiotics are ribosomally synthesized as precursor peptides consisting of an N-terminal leader and the propeptide sequence. The latter becomes posttranslationally modified by dehydration and thioether formation (49). The biochemistry of these modifications is still unknown but is associated in one group of lantibiotics with proteins LanB and LanC (24,35) and in a second group with LanM (16, 46; for review, see reference 47). A multimeric enzyme complex consisting of LanBTC was demonstrated for subtilin and nisin to be membrane associated and to catalyze modification and transport (32, 50).The B. subtilis strain A1/3 attracted our attention due to a broad spectrum of inhibitory activities against fungi and phytoviruses (28), as well as against diverse bacteria. Notable among these is the causative agent of tomato bacterial canker, Clavibacter michiganensis (20). In this paper we report the discovery of a lantibiotic gene cluster of B. subtilis A1/3, which shows conserved character to subtilin genes but encodes two distinct lantibiotic peptides, ericin S and ericin A. Both ericins were isolated from culture supernatants of B. subtilis A1/3, studied by high-performance liquid chromatography (HPLC), peptidase digestion, and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). The complete ericin gene cluster has been sequenced. Mutant studies indicated that both peptides are processed by the LanB homologue EriB. MATERIALS AND METHODSStrains, plasmids, and growth conditions. The original B. subtilis A1/3 (20, 28) contained at least two plasmids. A derivative GB709 of strain A1/3 was cured from plasmid DNA by repeated protoplasting and protoplast regeneration (8) and was used throughout these studies synonymously to A1/3, as it exhibited no detectable phenotypic differences from the parental strain. For antibiotic activity tests the following were used: B. subtilis strains DSM 402 (Spizi...

Evolution of lanthipeptide synthetases

“…2B). Interestingly, ericin S and A, despite possessing very different C-terminal ring topologies, are produced by the same biosynthetic enzymes (24). The D-ring of ericin S is linked to the E-ring in similar fashion as in nisin, whereas the D-ring of ericin A is intertwined with the C-ring, similar to that found in microbisporicin (Fig.…”

Expression and Functional Analysis of the Subtilin Immunity Genes spaIFEG in the Subtilin-Sensitive Host Bacillus subtilis MO1099

“…The sequence similarity of SpaG proteins (Fig. 1D) clearly argues against previously assigned translational start ATG codons of spaG (20) and eriG (35); putative TTG start codons, with the preceding appropriate ribosomal binding site GGAGG, are located 150 bp upstream of both the spaG and eriG genes. Remarkably, the derived protein regions are similar to corresponding regions of NisG, EpiG, SrtG, and MutG proteins, in particular, within highly conserved transmembrane domain (TMD) I ( Fig.…”

“…Thus, the organization of the subtilin immunity system (Fig. 1A) corresponds to closely related LanIFEG systems for ericin (35) and nisin (9,23) immunity.…”

Antibacterial peptides from thermophilic bacteria

“…Expressions of SpaRK are regulated by sporulation specific factor SigH, which is repressed during exponential growth by regulator AbrB (Fawcett et al, 2000). These data indicate that production of subilin is under dual control by culture density in quorum sensing mode, where subtilin response to the growth phases is directed by the Abrb/SigH (Stein et al, 2002b). …”