Structural and Functional Analysis of Cell Wall-anchored Polypeptide Adhesin BspA in Streptococcus agalactiae

• DOI: 10.1074/jbc.m116.726562
• Publication Date: 2016-06-17T01:15:26Z
• Authors: Sara Rego; Timothy J. Heal; Grace R. Pidwill; Marisa Till; Alice Robson; Richard J. Lamont; Richard B. Sessions; Howard F. Jenkinson; Paul R. Race; Angela H. Nobbs
• Keywords: 0301 basic medicine; 570; virulence factor; Bacterial Adhesion; Protein Structure, Secondary; Streptococcus agalactiae; Structure-Activity Relationship; 03 medical and health sciences; adhesin; Bacterial Proteins; Protein Domains; Cell Wall; Candida albicans; circular dichroism (CD); Humans; crystallography; isothermal titration calorimetry (ITC); Adhesins, Bacterial; Streptococcus; Membrane Proteins; molecular dynamics; AgI/II polypeptide; 3. Good health; Lactococcus lactis; Female

Streptococcus agalactiae (group B Streptococcus, GBS) is the predominant cause of early-onset infectious disease in neonates and responsible for life-threatening infections elderly immunocompromised individuals. Clinical manifestations GBS infection include sepsis, pneumonia, meningitis. Here, we describe BspA, a deviant antigen I/II family polypeptide that confers adhesive properties linked to pathogenesis GBS. Heterologous expression BspA on surface non-adherent bacterium Lactococcus lactis adherence scavenger receptor gp340, human vaginal epithelium, fungus Candida albicans. Complementary crystallographic biophysical characterization reveal novel β-sandwich adhesion domain unique asparagine-dependent super-helical stalk. Collectively, these findings establish new bacterial adhesin structure has effect been hijacked by pathogenic species provide competitive advantage mucosal infections.