Protein Domain : Porphyromonas gingivalis fimbrillin protein IPR008110

Type	Family
Description	Periodontal disease in humans is a major health problem in the developed world, and is caused by a number of specialised pathogens that inhabit the oral cavity. Amongst the bacterial species culturable from periodontal lesions are the streptococcal microbes Streptococcus mutans and Streptococcus sobrinus, and the Gram-negative anaerobe Porphyromonas gingivalis (Bacteroides gingivalis) [ ]. The latter bacterium has been implicated as the causative agent of peridontitis, pulpal infections and tonsillar abcesses [].Adherence by P. gingivalis to the periodontal surface is mediated by its major virulence factor fimbriae []. This differs from other pathogenic Gram-negative bacterial polymeric Type I and IV fimbriae/pili in that it is much more simplified, consisting of only a monomeric fimbrillin repeating subunit, Fma1/FimA. Fma1/FimA has a molecular weight of 43kDa, and can exhibit antigenic diversity in different P. gingivalis strains []. Unusually, this form of fimbrillin possesses a far longer leader peptide compared to the fimbrial subunits of other bacteria []. It has been hypothesised that this allows for the maturation of the preprotein during secretion [].Recently, a study into the different antigenic types of P. gingivalis fimbrillin classified them into five distinct groups, depending on their gene sequences [ ]. Investigations into the functional differences of each type revealed that in the majority of peridontitis cases, bacterial strains possessing the type II Fma1/FimA were the most prevalent []; in healthy adults, type I strains were the most common. This has implications for particular strains that are associated with periodontal disease.
Short Name	Fimbrillin