Skip to main content
. Author manuscript; available in PMC: 2021 Dec 1.
Published in final edited form as: Trends Microbiol. 2020 Jun 1;28(12):999–1009. doi: 10.1016/j.tim.2020.05.008

Figure 2: Assembly of the heterodimeric type 2 fimbrae in Actinomyces oris.

Figure 2:

(A) The type 2 fimbriae are encoded by the three-gene operon. Genes encoding the coaggregation factor CafA and the housekeeping sortase SrtA are located elsewhere. (B) Similar to the assembly mechanism of the SpaA pili, assembly of the type 2 fimbriae begins with translocation (Step 1) and post-translocational folding of the shaft pilin FimA and tip pilin FimB mediated by the disulfide bond-forming machine MdbA/VKOR coupled to the electron transport chain (ETC) (Step 2). Membrane-insertion (Step 3) of these pilins permits pilus polymerization catalyzed by the pilus-specific sortase SrtC2 (Step 4), followed by cell wall anchoring of the pilus polymer catalyzed by the housekeeping sortase SrtA; reproduced from Sanchez et al. [55].