title: Functional properties of type I and type II cytochromes c3 from Desulfovibrio africanus.
abstract: Type I cytochrome c(3) is a key protein in the bioenergetic metabolism of Desulfovibrio spp., mediating electron transfer between periplasmic hydrogenase and multihaem cytochromes associated with membrane bound complexes, such as type II cytochrome c(3). This work presents the NMR assignment of the haem substituents in type I cytochrome c(3) isolated from Desulfovibrio africanus and the thermodynamic and kinetic characterisation of type I and type II cytochromes c(3) belonging to the same organism. It is shown that the redox properties of the two proteins allow electrons to be transferred between them in the physiologically relevant direction with the release of energised protons close to the membrane where they can be used by the ATP synthase.
authors.affiliation: Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Rua da Quinta Grande, 6, Apt. 127, 2780-156 Oeiras, Portugal.
authors.forename: Catarina M
authors.initials: CM
authors.lastname: Paquete
authors.forename: Patrícia M
authors.initials: PM
authors.lastname: Pereira
authors.forename: Teresa
authors.initials: T
authors.lastname: Catarino
authors.forename: David L
authors.initials: DL
authors.lastname: Turner
authors.forename: Ricardo O
authors.initials: RO
authors.lastname: Louro
authors.forename: António V
authors.initials: AV
authors.lastname: Xavier
mesh_terms: D003574:Cytochrome c Group / Q000737:chemistry / Q000378:metabolism*; D045284:Desulfovibrio africanus / Q000737:chemistry*; D006418:Heme / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D019906:Nuclear Magnetic Resonance, Biomolecular; D010084:Oxidation-Reduction; D013816:Thermodynamics
chemical_list: D003574:Cytochrome c Group; D006418:Heme; C017165:cytochrome c(3)