Group B Streptococcus Surface Protein β: Structural Characterization of a Complement Factor H-Binding Motif and Its Contribution to Immune Evasion.

ABSTRACT: The β protein from group B Streptococcus (GBS) is a ∼132-kDa, cell-surface exposed molecule that binds to multiple host-derived ligands, including complement factor H (FH). Many details regarding this interaction and its significance to immune evasion by GBS remain unclear. In this study, we identified a three-helix bundle domain within the C-terminal half of the B75KN region of β as the major FH-binding determinant and determined its crystal structure at 2.5 Å resolution. Analysis of this structure suggested a role in FH binding for a loop region connecting helices α1 and α2, which we confirmed by mutagenesis and direct binding studies. Using a combination of protein cross-linking and mass spectrometry, we observed that B75KN bound to complement control protein (CCP)3 and CCP4 doma

SUBMITTER: Xu X 

PROVIDER: S-EPMC8881398 | biostudies-literature | 2022 Mar

REPOSITORIES: biostudies-literature