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A type VI secretion system delivers a cell wall amidase to target bacterial competitors
Author(s) -
Wang Tietao,
Hu Zhaoyu,
Du Xiao,
Shi Yue,
Dang Jing,
Lee Mijoon,
Hesek Dusan,
Mobashery Shahriar,
Wu Min,
Liang Haihua
Publication year - 2020
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.14513
Subject(s) - periplasmic space , biology , peptidoglycan , type vi secretion system , amidase , cell wall , pseudomonas aeruginosa , microbiology and biotechnology , bacteria , secretion , lysin , bacterial outer membrane , achromobacter , bacterial cell structure , biochemistry , pseudomonas , escherichia coli , genetics , virulence , gene , bacteriophage
The human pathogen Pseudomonas aeruginosa harbors three paralogous zinc proteases annotated as AmpD, AmpDh2, and AmpDh3, which turn over the cell wall and cell wall‐derived muropeptides. AmpD is cytoplasmic and plays a role in the recycling of cell wall muropeptides, with a link to antibiotic resistance. AmpDh2 is a periplasmic soluble enzyme with the former anchored to the inner leaflet of the outer membrane. We document, herein, that the type VI secretion system locus II (H2‐T6SS) of P. aeruginosa delivers AmpDh3 (but not AmpD or AmpDh2) to the periplasm of a prey bacterium upon contact. AmpDh3 hydrolyzes the cell wall peptidoglycan of the prey bacterium, which leads to its killing, thereby providing a growth advantage for P. aeruginosa in bacterial competition. We also document that the periplasmic protein PA0808, heretofore of unknown function, affords self‐protection from lysis by AmpDh3. Cognates of the AmpDh3‐PA0808 pair are widely distributed across Gram‐negative bacteria. Taken together, these findings underscore the importance of their function as an evolutionary advantage and that of the H2‐T6SS as the means for the manifestation of the effect.