2jxm
From Proteopedia
(New page: 200px<br /><applet load="2jxm" size="350" color="white" frame="true" align="right" spinBox="true" caption="2jxm" /> '''Ensemble of twenty structures of the Prochlo...) |
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==Overview== | ==Overview== | ||
| - | The nature of transient protein complexes can range from a highly dynamic | + | 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== | ==About this Structure== | ||
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[[Category: transport]] | [[Category: transport]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:06:25 2008'' |
Revision as of 16:06, 21 February 2008
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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
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