This entry represents C-terminal domain of proteins encoded by genes which are always found in type III secretion operons, although their function in the processes of secretion and virulence is unclear. Hpa stands for Hrp-associated gene, where Hrp stands for hypersensitivity response and virulence. see also PMID:18584024
Jiyao W et al.(2023). "The conserved domain database in 2023.",