IADR Abstract Archives

Characterization of Mfa3 in Mfa1 fimbriae of Porphyromonas gingivalis

Objectives:  Porphyromonas gingivalis, a primary causative agent of chronic periodontitis, has Mfa1 fimbriae considered to be an important factor for biofilm development. Recently PGN0289 (mfa3), PGN0290 and PGN0291, downstream genes of mfa1, were reported to produce accessory proteins of Mfa1 fimbriae. However, roles of accessory proteins in Mfa1 fimbriae were unclear. In this study, we investigated localization and function of Mfa3. 

Methods: A deletion mutant of mfa3 (Δmfa3) and specific antiserum against recombinant Mfa3 (α-Mfa3) were prepared. The subcellular localization of Mfa3 was determined by Western blotting using α-Mfa3. The localization of Mfa3 in fimbrial structure was examined by immuno-electron microscopy using α-Mfa3. Mfa1 fimbriae were purified from parent strain and Δmfa3 by ion exchange chromatography. Analysis of N-terminal amino acid was performed by Edman sequencing. The components of purified Mfa1 fimbriae from Δmfa3 were examined by SDS-PAGE and CBB stain. 

Results: Western blot analysis of whole cell lysate revealed that Mfa3 were present at two different sizes of 40 kDa and 43 kDa. The 43-kDa Mfa3 was detected largely in the inner membrane, whereas the 40-kDa Mfa3 was detected only in the purified Mfa1 fimbriae. N-terminal amino acid sequencing revealed that the 40-kDa Mfa3 started with the Ala44 residue of the deduced amino acid sequence. Immuno-electron microscopy revealed that Mfa3 localized at the tip of fimbrial structure. Other accessory proteins, PGN0290 and PGN0291, were absent in the purified Mfa1 fimbriae of Δmfa3.

Conclusions: These results suggest that N-terminal region of the primary translated protein from mfa3 gene is processed in the transport step from the inner membrane into the tip of Mfa1 fimbriae and that Mfa3 is required for incorporation/integration of PGN0290 and PGN0291 proteins into Mfa1 fimbriae. This study was supported by a grant (no. 22791783) from JSPS.

Japanese Division Meeting
2012 Japanese Division Meeting (Niigata, Japan)
Niigata, Japan
2012

Scientific Program
  • Hasegawa, Yoshiaki  ( Asahi University, Gifu, N/A, Japan )
  • Ikai, Ryota  ( Asahi University, Gifu, N/A, Japan )
  • Izumigawa, Masashi  ( Asahi University, Gifu, N/A, Japan )
  • Nagano, Keiji  ( Aichi Gakuin University, Aichi, N/A, Japan )
  • Kawabata, Atsushi  ( Asahi University, Gifu, N/A, Japan )
  • Kitai, Noriyuki  ( Asahi University, Gifu, N/A, Japan )
  • Yoshida, Yasuo  ( Aichi Gakuin University, Aichi, N/A, Japan )
  • Murakami, Yukitaka  ( Asahi University, Gifu, N/A, Japan )
  • Yoshimura, Fuminobu  ( Aichi Gakuin University, Aichi, N/A, Japan )
    • Microbiology/Immunology