5nf4 | pdb_00005nf4
The tip fimbrial protein Mfa3 from Porphyromonas gingivalis with C-terminal truncation.
Structural highlights
FunctionMFA3_PORG3 Tip subunit of the minor fimbriae. These filamentous pili are attached to the cell surface; they mediate biofilm formation, adhesion onto host cells and onto other bacteria that are part of the oral microbiome (PubMed:24118823, PubMed:26001707). They play an important role in invasion of periodontal tissues and are recognized as major virulence factors. Fimbrium subunits from different strains have highly divergent sequences, and this correlates with pathogenicity (Probable).[1] [2] Publication Abstract from PubMedVery little is known about how fimbriae of Bacteroidetes bacteria are assembled. To shed more light on this process, we solved the crystal structures of the shaft protein Mfa1, the regulatory protein Mfa2, and the tip protein Mfa3 from the periodontal pathogen Porphyromonas gingivalis. Together these build up part of the Mfa1 fimbria and represent three of the five proteins, Mfa1-5, encoded by the mfa1 gene cluster. Mfa1, Mfa2 and Mfa3 have the same overall fold i.e., two beta-sandwich domains. Upon polymerization, the first beta-strand of the shaft or tip protein is removed by indigenous proteases. Although the resulting void is expected to be filled by a donor-strand from another fimbrial protein, the mechanism by which it does so is still not established. In contrast, the first beta-strand in Mfa2, the anchoring protein, is firmly attached by a disulphide bond and is not cleaved. Based on the structural information, we created multiple mutations in P. gingivalis and analysed their effect on fimbrial polymerization and assembly in vivo. Collectively, these data suggest an important role for the C-terminal tail of Mfa1, but not of Mfa3, affecting both polymerization and maturation of downstream fimbrial proteins. Structural and functional characterization of shaft, anchor, and tip proteins of the Mfa1 fimbria from the periodontal pathogen Porphyromonas gingivalis.,Hall M, Hasegawa Y, Yoshimura F, Persson K Sci Rep. 2018 Jan 29;8(1):1793. doi: 10.1038/s41598-018-20067-z. PMID:29379120[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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