The structural gene of the lanthionine-containing peptide antibiotic epidermin is located on a 54-kb plasmid of Staphylococcus epidermidis [Schnelll et al. (1988) Nature 333, 276-2781. A 13.5-kb DNA region neighbouring the epidermin structural gene (@A) was subcloned and its sequencing revealed five additional open reading frames. Three of these reading frames, epiB, e p i c and epiD shared no homology with previously described proteins stored in data bases. They were located 3' adjacent to epiA. Using rpiB as a probe, a 5-kb mRNA was identified indicating that three or all four reading frames are transcribed as an operon. Additionally, a 0.3-kb mRNA specific for epiA was identified. Two open reading frames (epiP and epiQ) were located 3' to epiA, epiB, e p i c and epiD, but in the reverse orientation. The epiQ gene product shows similarity to the positive regulatory factor PhoB. This might indicate a regulatory function of epiQ in epidermin biosynthesis. The epiP gene product shows striking similarity to several serine proteases which makes epiP a likely candidate for processing the epidermin prepeptide. Heterologous epidermin synthesis in the non-producing organism Staphylococcus carnosus finally proved that these reading frames are necessary for epidermin biosynthesis.Epidermin is a 21-amino-acid peptide amide antibiotic with antimicrobial activities against Gram-positive bacteria. Some pathogenic bacteria in particular, such as Propionibacterium acnes, Staphylococci and Streptococci are highly sensitive to epidermin. It contains the unusual amino acid dehydrobutyrine and four sulfide rings consisting of two meso-kanthionine residues, one 3-methyllanthionine, and 2-aminovinyl-u-cysteine [I]. The isolation of the epidermin structural gene proved the ribosomal origin of this peptide antibiotic [2]. The primary translation product, called prepeptide, consists of 52 amino acid residues. Epidermin is derived by post-translational modification from the 22 C-terminal amino acid residues. The N-terminal 30 amino acids, which probably assume a partially amphiphilic a-helix conformation, were expected to play a cooperativc role during modification reactions [2]. A similar gene structure was confirmed for all lanthionine-containing peptide antibiotics investigated so far. These include Pep5 thesis of lantibiotics. The formation of the unusual non-proteinogenic amino acids could be explained by post-translational dehydration of peptide serine and threonine residues, with subsequent addition of cysteine sulfur to these dehydroamino acids [lo, 1 I].To elucidate the mechanism of how lantibiotics are posttranslationally modified and processed, the various enzymes involved have to be identified. Based on the prepeptide structure, our hypothesis indicates that modification reactions might occur at the entire prepeptide might occur 121. Two observations supported this view. First, in contrast to the Cterminus, the N-terminus of preepidermin contains mostly hydrophilic amino acid residues increasing propeptide solubility. Secon...

The production of the lanthionine-containing polypeptide antibiotics gallidermin from Staphylococcus gallinarum TU 3928 and pep 5 from S. epidermidis 5 is investigated with respect to regulation and stimulation of productivity by media components, optimization of both the media used and the fermentation process and is compared to the production of the lantibiotic epidermin from S. epidermidis TU 3298. Efficient methods for rapid quantification of lantibiotics, optimization of the media and a primary enrichment by adsorption chromatography are reported.