Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
J Mol Biol. 2011 Aug 19;411(3):713-27. doi: 10.1016/j.jmb.2011.06.027. Epub 2011 Jun 22.
Cellular functions of an organism are maintained by protein-protein interactions. Those proteins that bind multiple partners asynchronously (date hub proteins) are important to make the interaction network coordinated. It is known that many date hub proteins bind different partners at overlapping (OV) interfaces. To understand how OV interfaces of date hub proteins can recognize multiple partners, we analyzed the difference between OV and non-overlapping (Non-OV) regions of interfaces involved in the binding of different partners. By using the structures of 16 date hub proteins with various interaction partners (ranging from 5 to 33), we compared buried surface area, compositions of amino acid residues and secondary structures, and side-chain orientations. It was found that buried interface residues are important for recognizing multiple partners, while exposed interface residues are important for determining specificity to a particular ligand. In addition, our analyses reveal that residue compositions in OV and Non-OV regions are different and that residues in OV region show diverse side-chain torsion angles to accommodate binding to multiple targets.
生物体的细胞功能是通过蛋白质-蛋白质相互作用来维持的。那些能够异步结合多个伴侣的蛋白质（约会中心蛋白）对于使相互作用网络协调非常重要。已知许多约会中心蛋白在重叠（OV）界面上结合不同的伴侣。为了了解约会中心蛋白的 OV 界面如何能够识别多个伴侣，我们分析了涉及不同伴侣结合的界面的 OV 和非重叠（Non-OV）区域之间的差异。通过使用 16 种具有各种相互作用伴侣的约会中心蛋白的结构（范围从 5 到 33），我们比较了埋藏表面积、氨基酸残基组成和二级结构以及侧链取向。结果发现，埋藏的界面残基对于识别多个伴侣很重要，而暴露的界面残基对于确定对特定配体的特异性很重要。此外，我们的分析表明，OV 和 Non-OV 区域的残基组成不同，并且 OV 区域的残基显示出不同的侧链扭转角，以适应与多个靶标的结合。
