Identification and characterization of andalusicin: N-terminally dimethylated class III lantibiotic from Bacillus thuringiensis sv. andalousiensis

Summary

Lanthipeptides, ribosomally synthesized and post-translationally modified peptides (RiPPs), can be divided into five classes based on their structures and biosynthetic pathways. Class I and II lanthipeptides have been well characterized, whereas less is known about members of the other three classes. Here, we describe a new family of class III lanthipeptides from Firmicutes. Members of the family are distinguished by the presence of a single carboxy-terminal labionin. We identified and characterized andalusicin, a representative of this family. Andalusicin bears two methyl groups at the α-amino terminus, a post-translational modification that has not previously been identified in class III lanthipeptides. Mature andalusicin A shows bioactivity against various Gram-positive bacteria, an activity that is highly dependent on the α-N dimethylation.

Graphical abstract

Highlights

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  Type III lanthipeptide andalusicin A inhibits the growth of Gram-positive bacteria

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  Andalusicin A has an unusual pastor's crook structure

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  Genes encoding methyltransferases are frequently found in andalusicin-like BGCs

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  N-terminal methylation is necessary for andalusicin A biological activity

Abstract

Chemistry; Biosynthesis; Biochemistry; Medical biochemistry