title: Mapping the ligand-binding region of Borrelia burgdorferi fibronectin-binding protein BBK32.
abstract: The cellular attachment and entry of pathogenic microorganisms can be facilitated by the expression of microbial adhesins that bind fibronectin. We have previously described a Borrelia burgdorferi gene, bbk32, that encodes a 47-kDa fibronectin-binding protein. In this study, the ligand-binding region of BBK32 from B. burgdorferi isolate B31 was localized to 32 amino acids. The bbk32 gene was cloned and sequenced from three additional B. burgdorferi isolates representing different genospecies of B. burgdorferi sensu lato. All four bbk32 genes encoded proteins having fibronectin-binding activity when expressed in Escherichia coli, and the deduced proteins shared 81 to 91% amino acid sequence identity within the ligand-binding domain. In addition, the ligand-binding region of BBK32 was found to share sequence homology with a fibronectin-binding peptide defined for protein F1 of Streptococcus pyogenes. The structural and functional similarity between the ligand-binding region of BBK32 and the UR region of protein F1 suggests a common mechanism of cellular adhesion and entry for B. burgdorferi and S. pyogenes.
authors.affiliation: Division of Vector-Borne Infectious Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado 80522, USA.
authors.forename: W S
authors.initials: WS
authors.lastname: Probert
authors.forename: J H
authors.initials: JH
authors.lastname: Kim
authors.forename: M
authors.initials: M
authors.lastname: Höök
authors.forename: B J
authors.initials: BJ
authors.lastname: Johnson
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D015748:Borrelia burgdorferi Group / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D005353:Fibronectins / Q000378:metabolism*; D006801:Humans; D008024:Ligands; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013329:Structure-Activity Relationship
chemical_list: D001426:Bacterial Proteins; D005353:Fibronectins; D008024:Ligands; C106209:p35 antigen, Borrelia