forkhead associated (FHA) domain found in Yersinia enterocolitica Yop proteins translocation protein D (YscD) and similar proteins
YscD protein is a single-pass inner membrane protein required for the export process of the Yop proteins. It is an essential component of the type III secretion system. YscD protein contains an N-terminal cytoplasmic domain, a transmembrane linker and a large periplasmic domain. The cytoplasmic domain consists of a forkhead-associated (FHA) fold. The FHA domain is a small phosphopeptide recognition module. Due to the lack of the conserved residues that are required for binding phosphothreonine, the cytoplasmic domain of YscD protein is therefore unlikely to function as a true FHA domain.
Jiyao W et al.(2023). "The conserved domain database in 2023.",