DUF3380 domain from a Salmonella phage endolysin shows potent N-acetylmuramidase activity

Bacteriophage-encoded endolysins are highly diverse enzymes that cleave the bacterial peptidoglycan layer. Current research focuses on their potential applications in medicine, food conservation and as biotechnological tools. Despite the wealth of applications relying on the use of endolysin, little is known about the enzymatic properties of these enzymes, especially in case of endolysins of bacteriophages infecting Gram-negative species. Automated genome annotations therefore remain to be confirmed. Here, we report the biochemical analysis and cleavage site determination of a novel Salmonella bacteriophage endolysin, Gp110, which comprises an uncharacterized Domain of Unknown Function (DUF3380; pfam11860) domain in its C-terminus and shows the highest specific activity (34,240 U/μM) compared to fourteen previously characterized endolysins active against peptidoglycan from Gram-negative bacteria (corresponding to a 1.7- to 364-fold higher activity). Gp110 is a modular endolysin with an optimal pH of enzymatic activity at pH 8 and an elevated thermal resistance. Reversed phase-HPLC analysis coupled to mass spectrometry showed that DUF3380 has N-acetylmuramidase (lysozyme) activity cleaving the β- (1, 4) glycosidic bond between N-acetylmuramic acid and N-acetylglucosamine residues. Gp110 is active against directly cross-linked peptidoglycan with various peptide stem compositions, making it an attractive enzyme to develop novel antimicrobial agents.

Publication year:2016

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BOF-publication weight:1

CSS-citation score:2

Authors:International

Authors from:Higher Education

Accessibility:Open