Open AccessInner membrane proteins YgdD and SbmA are required for the complete susceptibility of Escherichia coli to the proline-rich antimicrobial peptide arasin 1(1–25)
Author(s) -
Victoria Paulsen,
Mario Mardirossian,
Hans-Matti Blencke,
Monica Benincasa,
Giulia Runti,
Matteo Nepa,
Tor Haug,
Klara Stensvåg,
Marco Scocchi
Publication year - 2016
Publication title -
microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.352
H-Index - 35
eISSN - 1465-2080
pISSN - 1350-0872
DOI - 10.1099/mic.0.000249
Subject(s) - escherichia coli , biology , mutant , peptide , gene , antimicrobial peptides , mode of action , inner membrane , antimicrobial , proline , bacteria , biochemistry , membrane protein , microbiology and biotechnology , genetics , amino acid , membrane
Arasin 1 from the spider crab Hyas araneus is a proline-rich antimicrobial peptide (PR-AMP), which kills target bacteria by a non-membranolytic mechanism. By using a fluorescent derivative of the peptide, we showed that arasin 1 rapidly penetrates into Escherichia coli cells without membrane damage. To unravel its mode of action, a knockout gene library of E. coli was screened and two types of mutants with a less susceptible phenotype to the arasin 1 fragment (1-23) were found. The first bore the mutation of sbmA , a gene coding for an inner membrane protein involved in the uptake of different antibiotic peptides. The second mutation was located in the ygdD gene, coding for a conserved inner membrane protein of unknown function. Functional studies showed that YgdD is required for the full susceptibility to arasin 1(1-25), possibly by supporting its uptake and/or intracellular action. These results indicated that different bacterial proteins are exploited by arasin 1(1-25) to exert its antibacterial activity and add new insights on the complex mode of action of PR-AMPs.