FIGURE 8.

Tentative models for the assembly and function of PceC in D. hafniense. (A) PceC (in yellow) is likely inserted in the cytoplasmic membrane while the FBD is in an unfolded state. (B) On the exocytoplasmic face of the membrane, Ftp (in blue) catalyzes the hydrolysis of FAD to FMN and AMP, and attaches FMN to the threonine-168 of PceC, resulting in the folding of the FBD. (C) PceC is hypothesized to build a protein complex with PceA (in red) and PceB (in orange), and to play the role of electron transfer from the menaquinol (MQ) pool to the redox centers of PceA via the FMN cofactor. Yellow diamonds represent the conserved CX₃CP sequence motifs.