Affiliation:
1. Department of Cariology, Umeå University, 901 87 Umeå, Sweden,1 and
2. Forsyth Dental Center, Boston, Massachusetts 021152
Abstract
ABSTRACT
Oral strains of
Actinomyces
spp. express type 1 fimbriae, which are composed of major FimP subunits, and bind preferentially to salivary acidic proline-rich proteins (APRPs) or to statherin. We have mapped genetic differences in the
fimP
subunit genes and the peptide recognition motifs within the host proteins associated with these differential binding specificities. The
fimP
genes were amplified by PCR from
Actinomyces viscosus
ATCC 19246, with preferential binding to statherin, and from
Actinomyces naeslundii
LY7, P-1-K, and B-1-K, with preferential binding to APRPs. The
fimP
gene from the statherin-binding strain 19246 is novel and has about 80% nucleotide and amino acid sequence identity to the highly conserved
fimP
genes of the APRP-binding strains (about 98 to 99% sequence identity). The novel FimP protein contains an amino-terminal signal peptide, randomly distributed single-amino-acid substitutions, and structurally different segments and ends with a cell wall-anchoring and a membrane-spanning region. When agarose beads with CNBr-linked host determinant-specific decapeptides were used,
A. viscosus
19246 bound to the Thr
42
Phe
43
terminus of statherin and
A. naeslundii
LY7 bound to the Pro
149
Gln
150
termini of APRPs. Furthermore, while the APRP-binding
A. naeslundii
strains originate from the human mouth,
A. viscosus
strains isolated from the oral cavity of rat and hamster hosts showed preferential binding to statherin and contained the novel
fimP
gene. Thus,
A. viscosus
and
A. naeslundii
display structurally variant
fimP
genes whose protein products are likely to interact with different peptide motifs and to determine animal host tropism.
Publisher
American Society for Microbiology
Subject
Infectious Diseases,Immunology,Microbiology,Parasitology
Cited by
32 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献