RT Journal Article SR Electronic(1) A1 Hasegawa, Yoshiaki A1 Iwami, Jun A1 Sato, Keiko A1 Park, Yoonsuk A1 Nishikawa, Kiyoshi A1 Atsumi, Tatsuo A1 Moriguchi, Keiichi A1 Murakami, Yukitaka A1 Lamont, Richard J. A1 Nakamura, Hiroshi A1 Ohno, Norikazu A1 Yoshimura, FuminobuYR 2009 T1 Anchoring and length regulation of Porphyromonas gingivalis Mfa1 fimbriae by the downstream gene product Mfa2 JF Microbiology, VO 155 IS 10 SP 3333 OP 3347 DO https://doi.org/10.1099/mic.0.028928-0 PB Microbiology Society, SN 1465-2080, AB Porphyromonas gingivalis, a causative agent of periodontitis, has at least two types of thin, single-stranded fimbriae, termed FimA and Mfa1 (according to the names of major subunits), which can be discriminated by filament length and by the size of their major fimbrilin subunits. FimA fimbriae are long filaments that are easily detached from cells, whereas Mfa1 fimbriae are short filaments that are tightly bound to cells. However, a P. gingivalis ATCC 33277-derived mutant deficient in mfa2, a gene downstream of mfa1, produced long filaments (10 times longer than those of the parent), easily detached from the cell surface, similar to FimA fimbriae. Longer Mfa1 fimbriae contributed to stronger autoaggregation of bacterial cells. Complementation of the mutant with the wild-type mfa2 allele in trans restored the parental phenotype. Mfa2 is present in the outer membrane of P. gingivalis, but does not co-purify with the Mfa1 fimbriae. However, co-immunoprecipitation demonstrated that Mfa2 and Mfa1 are associated with each other in whole P. gingivalis cells. Furthermore, immunogold microscopy, including double labelling, confirmed that Mfa2 was located on the cell surface and likely associated with Mfa1 fimbriae. Mfa2 may therefore play a role as an anchor for the Mfa1 fimbriae and also as a regulator of Mfa1 filament length. Two additional downstream genes (pgn0289 and pgn0290) are co-transcribed with mfa1 (pgn0287) and mfa2 (pgn0288), and proteins derived from pgn0289, pgn0290 and pgn0291 appear to be accessory fimbrial components., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.028928-0