The crystal structure of the hexadeca-heme cytochrome Hmc and a structural model of its complex with cytochrome c(3).
Sulfate-reducing bacteria contain a variety of multi-heme c-type cytochromes. The cytochrome of highest molecular weight (Hmc) contains 16 heme groups and is part of a transmembrane complex involved in the sulfate respiration pathway. We present the 2.42 A resolution crystal structure of the Desulfovibrio vulgaris Hildenborough cytochrome Hmc and a structural model of the complex with its physiological electron transfer partner, cytochrome c(3), obtained by NMR restrained soft-docking calculations. The Hmc is composed of three domains, which exist independently in different sulfate-reducing species, namely cytochrome c(3), cytochrome c(7), and Hcc. The complex involves the last heme at the C-terminal region of the V-shaped Hmc and heme 4 of cytochrome c(3), and represents an example for specific cytochrome-cytochrome interaction.
Czjzek
Mirjam
M
Architecture et Fonction des Macromolécules Biologiques, IBSM-CNRS et Université Aix-Marseille I et II, 31 Chemin Joseph-Aiguier, 13402 Marseille cedex 20, France. czjzek@afmb.cnrs-mrs.fr
ElAntak
Latifa
L
Zamboni
Véronique
V
Morelli
Xavier
X
Dolla
Alain
A
Guerlesquin
Françoise
F
Bruschi
Mireille
M
D018360:Crystallography, X-Ray; D003580:Cytochromes / Q000737:chemistry*; D006418:Heme / Q000737:chemistry*; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D011487:Protein Conformation
D003580:Cytochromes; D006418:Heme