title: Crystal structure of the regulatory subunit H of the V-type ATPase of Saccharomyces cerevisiae.
abstract: In contrast to the F-type ATPases, which use a proton gradient to generate ATP, the V-type enzymes use ATP to actively transport protons into organelles and extracellular compartments. We describe here the structure of the H-subunit (also called Vma13p) of the yeast enzyme. This is the first structure of any component of a V-type ATPase. The H-subunit is not required for assembly but plays an essential regulatory role. Despite the lack of any apparent sequence homology the structure contains five motifs similar to the so-called HEAT or armadillo repeats seen in the importins. A groove, which is occupied in the importins by the peptide that targets proteins for import into the nucleus, is occupied here by the 10 amino-terminal residues of subunit H itself. The structural similarity suggests how subunit H may interact with the ATPase itself or with other proteins. A cleft between the amino- and carboxyl-terminal domains also suggests another possible site of interaction with other factors.
authors: Institute of Molecular Biology, University of Oregon, Eugene, OR 97403-1229, USA.
authors: M
authors: M
authors: Sagermann
authors: T H
authors: TH
authors: Stevens
authors: B W
authors: BW
authors: Matthews
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017360:Arabidopsis / Q000201:enzymology; D017173:Caenorhabditis elegans / Q000201:enzymology; D029742:Caenorhabditis elegans Proteins; D018360:Crystallography, X-Ray; D004331:Drosophila melanogaster / Q000201:enzymology; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D021122:Protein Subunits; D017494:Proton Pumps / Q000737:chemistry; D006180:Proton-Translocating ATPases / Q000737:chemistry*; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D025262:Vacuolar Proton-Translocating ATPases
chemical_list: D029742:Caenorhabditis elegans Proteins; D021122:Protein Subunits; D017494:Proton Pumps; C506985:vha-11 protein, C elegans; C506986:vha-2 protein, C elegans; C506987:vha-3 protein, C elegans; D025262:Vacuolar Proton-Translocating ATPases; C506981:unc-32 protein, C elegans; D006180:Proton-Translocating ATPases