title: Subunit-subunit interactions and overall topology of the dimeric mitochondrial ATP synthase of Polytomella sp.
abstract: Mitochondrial F1F0-ATP synthase of chlorophycean algae is a dimeric complex of 1600 kDa constituted by 17 different subunits with varying stoichiometries, 8 of them conserved in all eukaryotes and 9 that seem to be unique to the algal lineage (subunits ASA1-9). Two different models proposing the topological assemblage of the nine ASA subunits in the ATP synthase of the colorless alga Polytomella sp. have been put forward. Here, we readdressed the overall topology of the enzyme with different experimental approaches: detection of close vicinities between subunits based on cross-linking experiments and dissociation of the enzyme into subcomplexes, inference of subunit stoichiometry based on cysteine residue labelling, and general three-dimensional structural features of the complex as obtained from small-angle X-ray scattering and electron microscopy image reconstruction. Based on the available data, we refine the topological arrangement of the subunits that constitute the mitochondrial ATP synthase of Polytomella sp.
authors.affiliation: Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F., Mexico.
authors.forename: Araceli
authors.initials: A
authors.lastname: Cano-Estrada
authors.forename: Miriam
authors.initials: M
authors.lastname: Vázquez-Acevedo
authors.forename: Alexa
authors.initials: A
authors.lastname: Villavicencio-Queijeiro
authors.forename: Francisco
authors.initials: F
authors.lastname: Figueroa-Martínez
authors.forename: Héctor
authors.initials: H
authors.lastname: Miranda-Astudillo
authors.forename: Yraima
authors.initials: Y
authors.lastname: Cordeiro
authors.forename: Julio A
authors.initials: JA
authors.lastname: Mignaco
authors.forename: Debora
authors.initials: D
authors.lastname: Foguel
authors.forename: Pierre
authors.initials: P
authors.lastname: Cardol
authors.forename: Marie
authors.initials: M
authors.lastname: Lapaille
authors.forename: Claire
authors.initials: C
authors.lastname: Remacle
authors.forename: Stephan
authors.initials: S
authors.lastname: Wilkens
authors.forename: Diego
authors.initials: D
authors.lastname: González-Halphen
mesh_terms: D000460:Chlorophyta / Q000201:enzymology*; D008854:Microscopy, Electron; D025261:Mitochondrial Proton-Translocating ATPases / Q000737:chemistry*; D055503:Protein Multimerization; D021122:Protein Subunits; D012542:Scattering, Radiation
chemical_list: D021122:Protein Subunits; D025261:Mitochondrial Proton-Translocating ATPases