2jxm
From Proteopedia
Ensemble of twenty structures of the Prochlorothrix hollandica plastocyanin- cytochrome f complex
Structural highlights
FunctionPLAS_PROHO Participates in electron transfer between P700 and the cytochrome b6-f complex in photosystem I. Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe nature of transient protein complexes can range from a highly dynamic ensemble of orientations to a single well-defined state. This represents variation in the equilibrium between the encounter and final, functional state. The transient complex between plastocyanin (Pc) and cytochrome f (cytf) of the cyanobacterium Prochlorothrix hollandica was characterized by NMR spectroscopy. Intermolecular pseudocontact shifts and chemical shift perturbations were used as restraints in docking calculations to determine the structure of the wild-type Pc-cytf complex. The orientation of Pc is similar to orientations found in Pc-cytf complexes from other sources. Electrostatics seems to play a modest role in complex formation. A large variability in the ensemble of lowest energy structures indicates a dynamic nature of the complex. Two unusual hydrophobic patch residues in Pc have been mutated to the residues found in other plastocyanins (Y12G/P14L). The binding constants are similar for the complexes of cytf with wild-type Pc and mutant Pc, but the chemical shift perturbations are smaller for the complex with mutant Pc. Docking calculations for the Y12G/P14L Pc-cytf complex did not produce a converged ensemble of structures. Simulations of the dynamics were performed using the observed averaged NMR parameters as input. The results indicate a surprisingly large amplitude of mobility of Y12G/P14L Pc within the complex. It is concluded that the double mutation shifts the complex further from the well-defined toward the encounter state. Dynamics in the transient complex of plastocyanin-cytochrome f from Prochlorothrix hollandica.,Hulsker R, Baranova MV, Bullerjahn GS, Ubbink M J Am Chem Soc. 2008 Feb 13;130(6):1985-91. Epub 2008 Jan 18. PMID:18201089[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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