2q4e

File:2q4e.jpg

spinqualitylabelsall models 2q4e, resolution 2.490Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Ensemble refinement of the protein crystal structure of gene product from Arabidopsis thaliana At4g09670

OverviewOverview

X-ray crystallography typically uses a single set of coordinates and B, factors to describe macromolecular conformations. Refinement of multiple, copies of the entire structure has been previously used in specific cases, as an alternative means of representing structural flexibility. Here, we, systematically validate this method by using simulated diffraction data, and we find that ensemble refinement produces better representations of, the distributions of atomic positions in the simulated structures than, single-conformer refinements. Comparison of principal components, calculated from the refined ensembles and simulations shows that concerted, motions are captured locally, but that correlations dissipate over long, distances. Ensemble refinement is also used on 50 experimental structures, of varying resolution and leads to decreases in R(free) values, implying, that improvements in the representation of flexibility observed for the, simulated structures may apply to real structures. These gains are, essentially independent of resolution or data-to-parameter ratio, suggesting that even structures at moderate resolution can benefit from, ensemble refinement.

About this StructureAbout this Structure

2Q4E is a Single protein structure of sequence from Arabidopsis thaliana. Full crystallographic information is available from OCA.

ReferenceReference

Ensemble refinement of protein crystal structures: validation and application., Levin EJ, Kondrashov DA, Wesenberg GE, Phillips GN Jr, Structure. 2007 Sep;15(9):1040-52. PMID:17850744

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