title: New complexes containing the internal alternative NADH dehydrogenase (Ndi1) in mitochondria of Saccharomyces cerevisiae.
abstract: Mitochondria of Saccharomyces cerevisiae lack the respiratory complex I, but contain three rotenone-insensitive NADH dehydrogenases distributed on both the external (Nde1 and Nde2) and internal (Ndi1) surfaces of the inner mitochondrial membrane. These enzymes catalyse the transfer of electrons from NADH to ubiquinone without the translocation of protons across the membrane. Due to the high resolution of the Blue Native PAGE (BN-PAGE) technique combined with digitonin solubilization, several bands with NADH dehydrogenase activity were observed on the gel. The use of specific S. cerevisiae single and double mutants of the external alternative elements (ΔNDE1, ΔNDE2, ΔNDE1/ΔNDE2) showed that the high and low molecular weight complexes contained the Ndi1. Some of the Ndi1 associations took place with complexes III and IV, suggesting the formation of respirasome-like structures. Complex II interacted with other proteins to form a high molecular weight supercomplex with a molecular mass around 600 kDa. We also found that the majority of the Ndi1 was in a dimeric form, which is in agreement with the recently reported three-dimensional structure of the protein.
authors.affiliation: Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Coyoacán 04510, México, D. F., México.
authors.forename: M G
authors.initials: MG
authors.lastname: Matus-Ortega
authors.affiliation: Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Coyoacán 04510, México, D. F., México.
authors.forename: C A
authors.initials: CA
authors.lastname: Cárdenas-Monroy
authors.affiliation: Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Coyoacán 04510, México, D. F., México.
authors.forename: O
authors.initials: O
authors.lastname: Flores-Herrera
authors.affiliation: Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Coyoacán 04510, México, D. F., México.
authors.forename: G
authors.initials: G
authors.lastname: Mendoza-Hernández
authors.affiliation: Department of Biological Sciences, University of Texas, El Paso, TX, USA.
authors.forename: M
authors.initials: M
authors.lastname: Miranda
authors.affiliation: Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Coyoacán 04510, México, D. F., México.
authors.forename: B
authors.initials: B
authors.lastname: González-Pedrajo
authors.affiliation: Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Coyoacán 04510, México, D. F., México.
authors.forename: H
authors.initials: H
authors.lastname: Vázquez-Meza
authors.affiliation: Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Coyoacán 04510, México, D. F., México.
authors.forename: J P
authors.initials: JP
authors.lastname: Pardo
mesh_terms: D019281:Dimerization; D004579:Electron Transport; D042967:Electron Transport Complex I / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008928:Mitochondria / Q000201:enzymology* / Q000235:genetics; D009243:NAD / Q000378:metabolism; D009245:NADH Dehydrogenase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: C493237:Ndi1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D009243:NAD; D009245:NADH Dehydrogenase; D042967:Electron Transport Complex I
keywords: Ndi1; Saccharomyces cerevisiae; alternative NADH dehydrogenase; respiratory supercomplexes; succinate dehydrogenase