Neutral evolution of model proteins: Diffusion in sequence space and overdispersion
Neutral evolution of model proteins: Diffusion in sequence space and overdispersion
复制标题
DOI：
10.1006/jtbi.1999.0975
复制
发表时间：
1999-09-07
影响因子：
2
通讯作者：
Vendruscolo, M
中科院分区：
文献类型：
--
作者：
Bastolla, U;Roman, HE;Vendruscolo, M
我们刺激受突变影响的模型蛋白质序列的进化。如果突变保持(1)基态结构，(2)热力学稳定性和(3)动力学可及性，则认为突变是中性的。所有其他突变都被认为是致命的，并被拒绝。我们采用晶格模型，能够可靠地解决蛋白质折叠问题。我们证明了序列空间中扩展神经网络的存在性-序列可以进化，直到它们与起始点的相似性几乎与随机序列相同。此外，我们发现中性突变率在序列空间中具有广泛的分布。由于这一事实，替代过程是过度分散的(方差与均值之比大于1)。这一结果与最简单的中性进化模型形成对比，该模型假设置换为泊松过程，并与生物学数据定性一致。(C)1999年学术出版社。
We stimulate the evolution of model protein sequences subject to mutations. A mutation is considered neutral if it conserves (1) the structure of the ground state, (2) its thermodynamic stability and (3) its kinetic accessibility. All other mutations are considered lethal and are rejected. We adopt a lattice model, amenable to a reliable solution of the protein folding problem. We prove the existence of extended neutral networks in sequence space-sequences can evolve until their similarity with the starting point is almost the same as for random sequences. Furthermore, we find that the rate of neutral mutations has a broad distribution in sequence space. Due to this fact, the substitution process is overdispersed (the ratio between variance and mean is larger than 1). This result is in contrast with the simplest model of neutral evolution, which assumes a Poisson process for substitutions, and in qualitative agreement with the biological data. (C) 1999 Academic Press.