Sampling rare events: Statistics of local sequence alignments
Sampling rare events: Statistics of local sequence alignments
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DOI：
10.1103/physreve.65.056102
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发表时间：
2002-05-01
影响因子：
2.4
通讯作者：
Hartmann, AK
中科院分区：
文献类型：
--
作者：
Hartmann, AK
一种计算事件非常不可能发生的区域中的概率分布的方法（例如，p类似于10（-40））。基本思想是将底层模型映射到物理系统上。在低温下模拟系统，使得优选地生成具有原始低概率的配置。由于这样一个物理系统的分布是已知的，所以可以得到原始的无偏分布。作为应用，研究了蛋白质序列的局部比对。量化了最优得分的分布p（S）与极值分布的偏差。这种偏差随着序列长度的增加而减小。
A method to calculate probability distributions in regions where the events are very unlikely (e.g., p similar to10(-40)) is presented. The basic idea is to map the underlying model on a physical system. The system is simulated at a low temperature, such that preferably configurations with originally low probabilities are generated. Since the distribution of such a physical system is known, the original unbiased distribution can be obtained. As an application, local alignment of protein sequences is studied. The deviation of the distribution p(S) of optimum scores from the extreme-value distribution is quantified. This deviation decreases with growing sequence length.