The type II secretion system (T2SS) is present in many Gram-negative bacteria and is responsible for secreting a large number of folded proteins, including major virulence factors, across the outer membrane. GspL (known in Vibrio species as EpsL) is a T2SS protein which interacts with several other T2SS proteins. The cytoplasmic domain of GspL (cyto-GspL) is responsible for the interactions with the first domain of GspE (an ATPase) and consists of three subdomains with similarities to proteins belonging to the actin-like ATPase superfamily. This entry represents the C-terminal subdomain of cyto-GspL PMID:25092625.