Predicted to enable ATPase binding activity. Predicted to contribute to proton-transporting ATPase activity, rotational mechanism. Predicted to be involved in proton transmembrane transport and vacuolar acidification. Predicted to be part of vacuolar proton-transporting V-type ATPase, V0 domain. Predicted to be active in plasma membrane. Is expressed in adult head; copper cell primordium; dorsal epidermis primordium; embryonic/larval midgut; and prothoracic gland. Human ortholog(s) of this gene implicated in autosomal recessive cutis laxa type IIA; autosomal recessive osteopetrosis 1; developmental and epileptic encephalopathy 104; renal tubular acidosis; and wrinkly skin syndrome. Orthologous to several human genes including ATP6V0A1 (ATPase H+ transporting V0 subunit a1); ATP6V0A2 (ATPase H+ transporting V0 subunit a2); and ATP6V0A4 (ATPase H+ transporting V0 subunit a4).