Characterization of the peripheral stalk of the vacuolar ATPase--subunit E : an honors thesis (HONRS 499)

Abstract

V-ATPases are multisubunit ATP-dependent proton pumps consisting of two domains: a peripheral V1 sector (subunits A-H), which binds and hydrolyses ATP, and a membrane-bound Vo sector (subunits a, c, c', c", d, and e), which forms the pore to proton transport. V 1 and Vo subunits are held together by one central stalk made of subunits D, F, and one (or two) peripheral stalks made of C, E, G, H and the N-end of subunit a.Subunit E (Vma 4) is a component of V1 that forms part of the peripheral stalk connecting V 1 and Vo. Although subunit E is essential for V-ATPase assembly, its function within the complex is not known. In order to better understand the function of the peripheral stalk subunit E, site-directed mutations were performed and the analysis of these mutants is presented here.