title: Subunit arrangement in V-ATPase from Thermus thermophilus.
abstract: The V0V1-ATPase of Thermus thermophilus catalyzes ATP synthesis coupled with proton translocation. It consists of an ATPase-active V1 part (ABDF) and a proton channel V0 part (CLEGI), but the arrangement of each subunit is still largely unknown. Here we found that acid treatment of V0V1-ATPase induced its dissociation into two subcomplexes, one with subunit composition ABDFCL and the other with EGI. Exposure of the isolated V0 to acid or 8 m urea also produced two subcomplexes, EGI and CL. Thus, the C subunit (homologue of d subunit, yeast Vma6p) associates with the L subunit ring tightly, and I (homologue of 100-kDa subunit, yeast Vph1p), E, and G subunits constitute a stable complex. Based on these observations and our recent demonstration that D, F, and L subunits rotate relative to A3B3 (Imamura, H., Nakano, M., Noji, H., Muneyuki, E., Ohkuma, S., Yoshida, M., and Yokoyama, K. (2003) Proc. Natl. Acad. Sci. U. S. A. 100, 2312-2315; Yokoyama, K., Nakano, M., Imamura, H., Yoshida, M., and Tamakoshi, M. (2003) J. Biol. Chem. 278, 24255-24258), we propose that C, D, F, and L subunits constitute the central rotor shaft and A, B, E, G, and I subunits comprise the surrounding stator apparatus in the V0V1-ATPase.
authors.affiliation: ATP System Project, ERATO, Japan Science and Technology Corp., 5800-3 Nagatsuta, Midori-ku, Yokohama 226-0026, Japan. kyokoyama-ra@res.titech.ac.jp
authors.forename: Ken
authors.initials: K
authors.lastname: Yokoyama
authors.forename: Koji
authors.initials: K
authors.lastname: Nagata
authors.forename: Hiromi
authors.initials: H
authors.lastname: Imamura
authors.forename: Shoji
authors.initials: S
authors.lastname: Ohkuma
authors.forename: Masasuke
authors.initials: M
authors.lastname: Yoshida
authors.forename: Masatada
authors.initials: M
authors.lastname: Tamakoshi
mesh_terms: D001483:Base Sequence; D008081:Liposomes; D008958:Models, Molecular; D020409:Molecular Motor Proteins; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010539:Permeability; D020836:Protein Structure, Quaternary; D021122:Protein Subunits / Q000302:isolation & purification*; D016963:Thermus thermophilus / Q000201:enzymology*; D025262:Vacuolar Proton-Translocating ATPases / Q000737:chemistry*
chemical_list: D008081:Liposomes; D020409:Molecular Motor Proteins; D021122:Protein Subunits; D025262:Vacuolar Proton-Translocating ATPases