. "\"A protein complex that forms part of a proton-transporting V-type ATPase and mediates proton transport across a membrane. The V0 complex consists of at least four different subunits (a,c,d and e); six or more c subunits form a proton-binding rotor ring.\" [GOC:mah, ISBN:0716743663, PMID:16449553]" . . "proton-transporting V-type ATPase, V0 domain" . .