Nishikawa K, Ooi T
Biochim Biophys Acta. 1986 May 12;871(1):45-54. doi: 10.1016/0167-4838(86)90131-7.
The assumption that homologous segments in different proteins may share a similar conformation is applied to the prediction of secondary structures in proteins. Sequences homologous to a target protein are searched, without allowing any gap, and compared against a number of reference proteins of known three-dimensional structure, and then a conformational state (alpha, beta or coil) for each residue of the protein is predicted by looking at the secondary structure of corresponding homologous segments. This prediction is done in a statistical rather than 'deterministic' way, by assigning the most probable conformation state among homologous data to each residue site of a target protein. A test application for 22 sample proteins yields 60% correctness on the average, a better value in comparison with two other existing methods. Joint prediction combining three methods into one is shown to increase the reliability up to 70%, when only the regions identically predicted with the three methods are taken into account. Application of the present method to 10 proteins of unknown structure is demonstrated.
不同蛋白质中的同源片段可能具有相似构象这一假设被应用于蛋白质二级结构的预测。搜索与目标蛋白质同源的序列，不允许有任何间隙，并与一些已知三维结构的参考蛋白质进行比较，然后通过查看相应同源片段的二级结构来预测蛋白质每个残基的构象状态（α、β或卷曲）。这种预测是以统计而非“确定性”的方式进行的，即通过将同源数据中最可能的构象状态分配给目标蛋白质的每个残基位点。对22个样本蛋白质的测试应用平均正确率为60%，与其他两种现有方法相比是更好的值。当仅考虑三种方法一致预测的区域时，将三种方法结合为一体的联合预测显示可靠性可提高到70%。展示了本方法在10个未知结构蛋白质上的应用。
