title: Localization and specificity of cytochromes and other electron transfer proteins from sulfate-reducing bacteria.
abstract: Recently data have accumulated concerning the electron transfer chains of sulfate-reducing bacteria in general and of the genus Desulfovibrio in particular. Because of the ever growing number of newly discovered individual redox proteins, it has become essential to try to assign them to physiologically relevant chains. This work presents some new data concerning the localization of these proteins within the bacterial cell and the specificity of electron transfer between the three types of hydrogenases which have been found so far in Desulfovibrio, namely the iron-only, the iron-nickel and the iron-nickel-selenium enzymes. The iron-only hydrogenase reduces cytochromes which have bis-histidinyl heme ligation or histidinyl-methionyl heme ligation. In contrast, the iron-nickel and iron-nickel-selenium hydrogenases cannot reduce cytochromes having a His-Met heme ligation, but are very active toward the cytochromes having a bis-histidinyl ligand. This observation has been used to demonstrate that the tetraheme cytochrome c3 can exchange electrons with the monoheme cytochrome c553. No clear specificity has been established for the reaction of hydrogenases toward the hexadecaheme cytochromes from either D vulgaris or D gigas.
authors.affiliation: Department of Biochemistry, University of Georgia, Athens 30602-7229.
authors.forename: J
authors.initials: J
authors.lastname: Le Gall
authors.forename: W J
authors.initials: WJ
authors.lastname: Payne
authors.forename: L
authors.initials: L
authors.lastname: Chen
authors.forename: M Y
authors.initials: MY
authors.lastname: Liu
authors.forename: A V
authors.initials: AV
authors.lastname: Xavier
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism*; D003574:Cytochrome c Group / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism*; D003901:Desulfovibrio / Q000254:growth & development / Q000378:metabolism*; D016969:Desulfovibrio vulgaris / Q000378:metabolism; D004579:Electron Transport; D005288:Ferredoxins / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism*; D006422:Hemerythrin; D006864:Hydrogenase / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism*; D050885:Hydrogensulfite Reductase; D008969:Molecular Sequence Data; D050862:Oxidoreductases Acting on Sulfur Group Donors / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism; D021382:Protein Sorting Signals / Q000737:chemistry; D012416:Rubredoxins; D013347:Subcellular Fractions / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D003574:Cytochrome c Group; D005288:Ferredoxins; D006422:Hemerythrin; D021382:Protein Sorting Signals; D012416:Rubredoxins; C083951:cytochrome c553; C055857:rubrerythrins; C017165:cytochrome c(3); C022302:cytochrome C-552; D006864:Hydrogenase; D050862:Oxidoreductases Acting on Sulfur Group Donors; D050885:Hydrogensulfite Reductase