MERSACIDIN IS A GLOBULAR TYPE B LANTIBIOTIC. THE LANTIBIOTICS ARE CHARACTERIZED BY THIOETHER AMINO ACIDS LANTHIONINE AND/OR METHYLLANTHIONINE. HERE, MERSACIDIN IS REPRESENTED BY THE SEQUENCE (SEQRES)
MERSACIDIN IS A TETRACYCLIC PEPTIDE. POST TRANSLATIONAL MATURATION OF LANTIBIOTICS INVOLVES THE ENZYMIC CONVERSION OF THR, AND SER INTO DEHYDRATED AA AND THE FORMATION OF THIOETHER BONDS WITH CYSTEINE. THE CARBOXY-TERMINAL BETA-METHYLLANTHIONINE UNDERGOES DECARBOXYLATION. THIOETHER BONDS WITH CYSTEINE RESULT IN FOUR RINGS. THIS IS FOLLOWED BY MEMBRANE TRANSLOCATION AND CLEAVAGE OF THE MODIFIED PRECURSOR.