ANALYSIS OF PACKING CONTACTS IN PROTEIN CRYSTALS

本项目的目标是确定包装的共同特征 蛋白质晶体中的相互作用，通过对结构的统计调查 布鲁克海文蛋白质数据库。我们使用了PKB中的函数 用于识别蛋白质中的非冗余结构子集的套件 具有有效晶体对称性信息的数据库。为了这些 结构，我们有按残留物和 残基配对类型，并进行统计分析。一个有趣的故事 确定的特征是氨基酸的优先参与 带有小的侧链，表明晶格填充在 衍射级晶体必须包含严格的分子内接触 多肽的主干。另一个有趣的特征是一个明确的 填充触点密度与分辨率的关系 现有的衍射数据，表明晶格堆积可以 减少晶体紊乱。这个项目的意义在于 提供了蛋白质之间相互作用的摘要，如 水晶。这些与分子内或 低聚物-对接接触，它们可能提供相互作用的模型 预计在松散关联的生物复合体中。

The goal of this project is to identify common features of packing interactions in protein crystals, by statistical survey of structures in the Brookhaven Protein Data Bank. We have used functions in the PKB suite to identify a non-redundant subset of structures in the Protein Data Bank which have valid crystal symmetry information. For these structure we have tabulated crystal-packing contacts by residue and residue-pair type, and conducted statistical analyses. An interesting feature identified is the preferential participation of amino acids with small side chains, suggesting that lattice packing in diffraction-quality crystals must involve rigid intra-molecular contact of the polypeptide backbone. Another interesting feature is a clear correlation between the density of packing contacts and the resolution of available diffraction data, suggesting that lattice packing can reduce crystal disorder. The significance of this project is in providing a summary of protein-protein interactions as observed in crystals. These are very different from intra-molecular or oligomer-docking contacts, and they may provide a model for interactions expected in loosely-associated biological complexes.