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Updated: May 9, 2026

Antimicrobial Peptides Produced by Selective Pressure Incorporation of Non-canonical Amino Acids
Published on: May 4, 2018
NSR from Streptococcus agalactiae confers resistance against nisin and is encoded by a conserved nsr operon
Abstract:
Nisin is a lantibiotic produced by Lactococcus lactis (L. lactis), which is active against many Gram-positive bacteria. However, in various pathogenic and nonpathogenic bacteria, the presence of a nisin resistance protein (NSR) confers resistance against nisin. Here, we show that NSR from Streptococcus agalactiae (SaNSR) confers 20-fold resistance when expressed in L. lactis. We also show that SaNSR is encoded by an operon structure comprising of a lipoprotein and an ATP-binding cassette transporter as well as a two-component system that is putatively involved in expression and regulation. This organization of the operon is conserved in several (non)pathogenic strains that do not produce nisin themselves.
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