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A novel peptidoglycan D , L ‐endopeptidase induced by S almonella inside eukaryotic cells contributes to virulence
Author(s) -
RicoPérez Gadea,
Pezza Alejandro,
Pucciarelli M. Graciela,
Pedro Miguel A.,
Soncini Fernando C.,
Garcíadel Portillo Francisco
Publication year - 2016
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.13248
Subject(s) - peptidoglycan , biology , virulence , endopeptidase , microbiology and biotechnology , biochemistry , cell wall , gene , enzyme
Summary Bacteria remodel peptidoglycan structure in response to environmental changes. Many enzymes are involved in peptidoglycan metabolism; however, little is known about their responsiveness in a defined environment or the modes they assist bacteria to adapt to new niches. Here, we focused in peptidoglycan enzymes that intracellular bacterial pathogens use inside eukaryotic cells. We identified a peptidoglycan enzyme induced by S almonella enterica serovar Typhimurium in fibroblasts and epithelial cells. This enzyme, which shows γ‐D‐glutamyl‐ meso ‐diaminopimelic acid D , L ‐endopeptidase activity, is also produced by the pathogen in media with limited nutrients and in resting conditions. The enzyme, termed EcgA for e ndopeptidase responding to c essation of g rowth’, is encoded in a S . Typhimurium genomic island absent in E scherichia coli . EcgA production is strictly dependent on the virulence regulator PhoP in extra‐ and intracellular environments. Consistent to this regulation, a mutant lacking EcgA is attenuated in the mouse typhoid model. These findings suggest that specialised peptidoglycan enzymes, such as EcgA , might facilitate S almonella adaptation to the intracellular lifestyle. Moreover, they indicate that readjustment of peptidoglycan metabolism inside the eukaryotic cell is essential for host colonisation.