Isolation and characterization of Fap1, a fimbriae-associated adhesin of Streptococcus parasanguis FW213.
An adhesin of Streptococcus parasanguis FW213, a primary colonizer of the tooth surface, has been purified from the culture medium by immunoaffinity chromatography. The purified protein has a molecular mass of 200 kDa and stains positively for carbohydrate. The amino-terminal sequence indicated that this protein represented a unique streptococcal surface protein. Immunogold labelling of the bacterium indicated that this protein was associated with fimbriae and designated Fap1 (fimbriae-associated protein). A polymerase chain reaction (PCR) product based on the amino terminus of Fap1 was used to probe an FW213 genomic library. A 9 kb fragment containing the fap1 gene was isolated and 2.5 kb have been sequenced. Generation of fap1 mutants by a single cross-over (Campbell insertion) or a non-polar allelic exchange abolished the expression of Fap1. The inactivation of fap1 resulted in a dramatic reduction in the expression of the long peritrichous fimbriae and adhesion to saliva-coated hydroxylapatite (SHA). Northern blots probed with an internal gene fragment of fap1 hybridized to a 9 kb transcript, which suggests that fap1 is transcribed as a polycistronic message. These data demonstrate that Fap1 is a unique streptococcal adhesin that is involved in the assembly of S. parasanguis FW213 fimbriae and adhesion to SHA.
Wu
H
H
Department of Microbiology and Molecular Genetics, College of Medicine, University of Vermont, Burlington 05405, USA.
Mintz
K P
KP
Ladha
M
M
Fives-Taylor
P M
PM
D018829:Adhesins, Bacterial / Q000032:analysis / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D000595:Amino Acid Sequence; D001422:Bacterial Adhesion; D015152:Blotting, Northern; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D010861:Fimbriae, Bacterial / Q000737:chemistry* / Q000648:ultrastructure; D005798:Genes, Bacterial; D006801:Humans; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D015183:Restriction Mapping; D013291:Streptococcus / Q000737:chemistry* / Q000235:genetics / Q000502:physiology / Q000648:ultrastructure
D018829:Adhesins, Bacterial