Detected putative lasso peptides. A Microcin J25 (mcj) (E. coli) and Lariatin (lar) (R. jostii K01-B0171) gene clusters in comparision to putative lasso peptide gene clusters of G. uraniireducens Rf4, P. propionicus DSM 2379, D. acetoxidans DSM 11069 (* = precursor peptide identified in this study, # = precursor peptide identified by ), B. proteoclasticum B313, D. acetoxidans DSM 771, S. glycolicus DSM 8271 and C. perfringens str. 13; Annotation of the putative precursor peptide was not conclusively possible in most cases; Numbers represent the locus tag for each gene within the genome sequence of each organism. B Cleavage of the lariatin precursor peptide by a putative protease (LarD); Isopeptide bond (green) formation by LarB between the N-terminal amino acid glycine (red) and a glutamate (red) leads to the formation of a 8- membered macrolactame ring in lariatin. C Lasso peptide structure of lariatin (isopeptide bond (green)).