Biophysics and Molecular Modeling Group, Department of Physics, Huazhong University of Science and Technology, Wuhan, China.
PLoS One. 2010 Nov 30;5(11):e14138. doi: 10.1371/journal.pone.0014138.
To understand how symmetric structures of many proteins are formed from asymmetric sequences, the proteins with two repeated beta-trefoil domains in Plant Cytotoxin B-chain family and all presently known beta-trefoil proteins are analyzed by structure-based multi-sequence alignments. The results show that all these proteins have similar key structural residues that are distributed symmetrically in their structures. These symmetric key structural residues are further analyzed in terms of inter-residues interaction numbers and B-factors. It is found that they can be distinguished from other residues and have significant propensities for structural framework. This indicates that these key structural residues may conduct the formation of symmetric structures although the sequences are asymmetric.
为了理解许多蛋白质的对称结构是如何由不对称序列形成的，对植物细胞毒素 B 链家族中具有两个重复 β-三叶因子结构域的蛋白质和所有已知的β-三叶因子蛋白质进行了基于结构的多序列比对分析。结果表明，所有这些蛋白质都具有相似的关键结构残基，这些残基在结构中呈对称分布。进一步对这些对称关键结构残基的残基间相互作用数和 B 因子进行了分析。结果发现，它们可以与其他残基区分开来，并且对结构框架有显著的倾向性。这表明，尽管序列是不对称的，但这些关键结构残基可能有助于对称结构的形成。
