Your browser doesn't support javascript.
loading
PgaB orthologues contain a glycoside hydrolase domain that cleaves deacetylated poly-ß(1,6)-N-acetylglucosamine and can disrupt bacterial biofilms.
Little, Dustin J; Pfoh, Roland; Le Mauff, François; Bamford, Natalie C; Notte, Christina; Baker, Perrin; Guragain, Manita; Robinson, Howard; Pier, Gerald B; Nitz, Mark; Deora, Rajendar; Sheppard, Donald C; Howell, P Lynne.
Afiliação
  • Little DJ; Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada.
  • Pfoh R; Department of Biochemistry, University of Toronto, Toronto, ON, Canada.
  • Le Mauff F; Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada.
  • Bamford NC; Departments of Medicine and of Microbiology and Immunology, McGill University, Montréal, QC, Canada.
  • Notte C; Infectious Diseases and Immunity in Global Health Program, Research Institute of the McGill University Health Centre, Montréal, QC, Canada.
  • Baker P; Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada.
  • Guragain M; Department of Biochemistry, University of Toronto, Toronto, ON, Canada.
  • Robinson H; Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada.
  • Pier GB; Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada.
  • Nitz M; Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, NC, United States of America.
  • Deora R; Department of Microbial Infection and Immunity, The Ohio State University Wexner Medical Center, Columbus, OH, United States of America.
  • Sheppard DC; Photon Sciences Division, Brookhaven National Laboratory, Upton, NY, United States of America.
  • Howell PL; Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States of America.
PLoS Pathog ; 14(4): e1006998, 2018 04.
Article em En | MEDLINE | ID: mdl-29684093
Poly-ß(1,6)-N-acetyl-D-glucosamine (PNAG) is a major biofilm component of many pathogenic bacteria. The production, modification, and export of PNAG in Escherichia coli and Bordetella species require the protein products encoded by the pgaABCD operon. PgaB is a two-domain periplasmic protein that contains an N-terminal deacetylase domain and a C-terminal PNAG binding domain that is critical for export. However, the exact function of the PgaB C-terminal domain remains unclear. Herein, we show that the C-terminal domains of Bordetella bronchiseptica PgaB (PgaBBb) and E. coli PgaB (PgaBEc) function as glycoside hydrolases. These enzymes hydrolyze purified deacetylated PNAG (dPNAG) from Staphylococcus aureus, disrupt PNAG-dependent biofilms formed by Bordetella pertussis, Staphylococcus carnosus, Staphylococcus epidermidis, and E. coli, and potentiate bacterial killing by gentamicin. Furthermore, we found that PgaBBb was only able to hydrolyze PNAG produced in situ by the E. coli PgaCD synthase complex when an active deacetylase domain was present. Mass spectrometry analysis of the PgaB-hydrolyzed dPNAG substrate showed a GlcN-GlcNAc-GlcNAc motif at the new reducing end of detected fragments. Our 1.76 Å structure of the C-terminal domain of PgaBBb reveals a central cavity within an elongated surface groove that appears ideally suited to recognize the GlcN-GlcNAc-GlcNAc motif. The structure, in conjunction with molecular modeling and site directed mutagenesis led to the identification of the dPNAG binding subsites and D474 as the probable catalytic acid. This work expands the role of PgaB within the PNAG biosynthesis machinery, defines a new glycoside hydrolase family GH153, and identifies PgaB as a possible therapeutic agent for treating PNAG-dependent biofilm infections.
Assuntos

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Bordetella / Biofilmes / Proteínas de Escherichia coli / Beta-Glucanas / Escherichia coli / Amidoidrolases / Glicosídeo Hidrolases Idioma: En Ano de publicação: 2018 Tipo de documento: Article

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Bordetella / Biofilmes / Proteínas de Escherichia coli / Beta-Glucanas / Escherichia coli / Amidoidrolases / Glicosídeo Hidrolases Idioma: En Ano de publicação: 2018 Tipo de documento: Article