title: Structure of the intermolecular complex between plastocyanin and cytochrome f from spinach.
abstract: In oxygenic photosynthesis, plastocyanin shuttles electrons between the membrane-bound complexes cytochrome b6f and photosystem I. The homologous complex between cytochrome f and plastocyanin, both from spinach, is the object of this study. The solution structure of the reduced spinach plastocyanin was determined using high field NMR spectroscopy, whereas the model structure of oxidized cytochrome f was obtained by homology modeling calculations and molecular dynamics. The model structure of the intermolecular complex was calculated using the program AUTODOCK, taking into account biological information obtained from mutagenesis experiments. The best electron transfer pathway from the heme group of cytochrome f to the copper ion of plastocyanin was calculated using the program HARLEM, obtaining a coupling decay value of 1.8 x 10(-4). Possible mechanisms of interaction and electron transfer between plastocyanin and cytochrome f were discussed considering the possible formation of a supercomplex that associates one cytochrome b6f, one photosystem I, and one plastocyanin.
authors.affiliation: Laboratory of Bioinorganic Chemistry, Department of Agro-Environmental Science and Technology, University of Bologna, Viale Giuseppe Fanin 40, 40127 Bologna, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Musiani
authors.forename: Alexander
authors.initials: A
authors.lastname: Dikiy
authors.forename: Alexey Yu
authors.initials: AY
authors.lastname: Semenov
authors.forename: Stefano
authors.initials: S
authors.lastname: Ciurli
mesh_terms: D000465:Algorithms; D000595:Amino Acid Sequence; D003300:Copper / Q000737:chemistry; D045346:Cytochrome b6f Complex / Q000737:chemistry; D045348:Cytochromes f / Q000737:chemistry* / Q000378:metabolism; D006418:Heme / Q000737:chemistry; D007477:Ions; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009154:Mutation; D010100:Oxygen / Q000378:metabolism; D045331:Photosystem I Protein Complex / Q000737:chemistry; D010970:Plastocyanin / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017386:Sequence Homology, Amino Acid; D012984:Software; D018724:Spinacia oleracea / Q000378:metabolism*; D013997:Time Factors
chemical_list: D007477:Ions; D045331:Photosystem I Protein Complex; D006418:Heme; D003300:Copper; D010970:Plastocyanin; D045346:Cytochrome b6f Complex; D045348:Cytochromes f; D010100:Oxygen