Amended Description of the Genes for Synthesis of Actinomyces naeslundii T14V Type 1 Fimbriae and Associated Adhesin
Abstract
Studies of the prominent oral microorganism Actinomyces naeslundii have provided important insights into both the properties of fimbriae or pili on gram-positive bacteria (16, 18) and the underlying mechanisms of dental plaque formation (4). The fimbriae of A. naeslundii , which were among the first observed for a gram-positive species (11), consist of two functionally distinct types (5). The type 1 fimbriae mediate adhe- sion of this species to the tooth surface through the binding of adsorbed salivary proline-rich proteins (PRPs) (7, 10, 13), whereas the type 2 fimbriae promote biofilm formation (14) through recognition of hostlike saccharide motifs in the surface polysaccharides of early colonizing streptococci (3). The major subunits of type 1 and type 2 fimbriae, encoded by the genes fimP (19) and fimA (20), respectively, are similar in size (56 kDa) and have sequences that are approximately 40% identical. The gene fimA of A. naeslundii T14V occurs between open reading frame 977 (ORF 977), which may encode the type 2 fimbria-associated adhesin (12), and ORF 365 for a sortase that is required for the covalent polymerization of FimA monomers (20). In contrast, fimP of this strain appears to be flanked by three essential upstream ORFs (i.e., ORF3-ORF2-ORF1) of unknown function and two essential downstream ORFs (i.e., ORF4-ORF5) (22), which include the partial coding sequence of a putative sortase (9). Moreover, the genes that reportedly flank fimP in strain T14V differ dramatically from those that flank this gene in type 1-fimbriated Actinomyces viscosus 19246 (13).
Document Details
- Document Type
- Technical Report
- Publication Date
- May 07, 2007
- Accession Number
- ADA629279
Entities
People
- Jenny T. Ho
- John O. Cisar
- Kai Poon Leung
- Ping Chen
- Sonja Hess
Organizations
- United States Army Institute of Surgical Research