Using a conformation-dependent stereochemical library improves crystallographic refinement of proteins
- 19 June 2010
- journal article
- research article
- Published by International Union of Crystallography (IUCr) in Acta Crystallographica Section D Structural Biology
- Vol. 66 (7) , 834-842
Abstract
The major macromolecular crystallographic refinement packages restrain models to ideal geometry targets defined as single values that are independent of molecular conformation. However, ultrahigh-resolution X-ray models of proteins are not consistent with this concept of ideality and have been used to develop a library of ideal main-chain bond lengths and angles that are parameterized by the φ/ψ angle of the residue [Berkholzet al.(2009),Structure,17, 1316–1325]. Here, it is first shown that the new conformation-dependent library does not suffer from poor agreement with ultrahigh-resolution structures, whereas current libraries have this problem. Using theTNTrefinement package, it is then shown that protein structure refinement using this conformation-dependent library results in models that have much better agreement with library values of bond angles with little change in theRvalues. These tests support the value of revising refinement software to account for this new paradigm.Keywords
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