2jxm
From Proteopedia
|
Ensemble of twenty structures of the Prochlorothrix hollandica plastocyanin- cytochrome f complex
Overview
The 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.
About this Structure
2JXM is a Protein complex structure of sequences from Prochlorothrix hollandica with and as ligands. Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
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
Page seeded by OCA on Wed Feb 13 08:19:31 2008
