Interaction between subunit C (Vma5p) of the yeast vacuolar ATPase and the stalk of the C-depleted V1 ATPase from Manduca sexta midgut

Projection maps of a V1-Vma5p hybrid complex, composed of subunit C (Vma5p) of Saccharomyces cerevisiae V-ATPase and the C-depleted V1 from Manduca sexta, were determined from single particle electron microscopy. V1-Vma5p consists of a headpiece and an elongated wedgelike stalk with a 2.1×3.0 nm protuberance and a 9.5×7.5 globular domain, interpreted to include Vma5p. The interaction face of Vma5p in V1 was explored by chemical modification experiments.