Lantibiotics are ribosomally synthesised antimicrobial agents derived from ribosomally synthesised peptides [1]. They are produced by bacteria of the Firmicutes phylum, and include mutacin, subtilin, and nisin. Lantibiotic peptides contain thioether bridges termed lanthionines that are thought to be generated by dehydration of serine and threonine residues followed by addition of cysteine residues [2]. This family constitutes the N-terminus of the enzyme proposed to catalyse the dehydration step [2],[3] via glutamylation of the substrate during lantibiotic biosynthesis. The enzyme dehydrates Ser/Thr residues in the precursor by glutamylation [4].

1: Analysis of genes involved in biosynthesis of the lantibiotic subtilin. Klein C, Kaletta C, Schnell N, Entian KD; Appl Environ Microbiol 1992;58:132-142. PMID:1539969

2: Heterologous expression and purification of SpaB involved in subtilin biosynthesis. Xie L, Chatterjee C, Balsara R, Okeley NM, van der Donk WA; Biochem Biophys Res Commun 2002;295:952-957. PMID:12127987

3: Post-translational modification of nisin. The involvement of NisB in the dehydration process. Karakas Sen A, Narbad A, Horn N, Dodd HM, Parr AJ, Colquhoun I, Gasson MJ; Eur J Biochem 1999;261:524-532. PMID:10215865

4: Structure and mechanism of the tRNA-dependent lantibiotic dehydratase NisB. Ortega MA, Hao Y, Zhang Q, Walker MC, van der Donk WA, Nair SK; Nature. 2014; [Epub ahead of print] PMID:25363770