V-type proton ATPase 21 kDa proteolipid subunit (ATP6F/ATP6V0B) and similar proteins
ATP6F (also called V-ATPase 21 kDa proteolipid subunit, or vacuolar proton pump 21 kDa proteolipid subunit) is a proton-conducting pore forming subunit of the membrane integral Vo complex of vacuolar ATPase. V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells.