Novel structure of the N-terminal helical domain of BibA, a group B streptococcus immunogenic bacterial adhesin.

ABSTRACT: BibA, a group B streptococcus (GBS) surface protein, has been shown to protect the pathogen from phagocytic killing by sequestering a complement inhibitor: C4b-binding protein (C4BP). Here, the X-ray crystallographic structure of a GBS BibA fragment (BibA_126-398) and a low-resolution small-angle X-ray scattering (SAXS) structure of the full-length N-terminal domain (BibA_34-400) are described. The BibA_126-398 fragment crystal structure displayed a novel and predominantly helical structure. The tertiary arrangement of helices forms four antiparallel three-helix-bundle-motif repeats, with one long helix from a bundle extending into the next. Multiple mutations on recombinant BibA_34-400 delayed the degradation of the protein, and circular dichroism s

SUBMITTER: Manne K 

PROVIDER: S-EPMC7397492 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature