Function
FhaC membrane transporter is a protein in the Omp85 family. It involves two polypeptide-transport associated (POTRA) domains, which are involved in substrate recognition. This protein's main function is to aid in FHA, or filamentous hemagglutinin, secretion. This is carried out by a two-partner secretion system, where FhaC is the translocase and FHA is the substrate. The beta-barrel conformation provides the pore for FHA transport through the membrane of the cell. The substrate is involved in a competitive mechanism with a linker protein, H1 helix, that normally rests inside of the barrel to block transport. This helix interacts weakly with the POTRA2 domain, to sit inside the pore. When the substrate (FHA) arrives at the transport site, it competes with the linker protein for the interaction with the POTRA2 domain. This pushes the H1 helix out, allowing the pore to be used for FHA secretion. [1]
Disease
Relevance
Structural highlights
