Structural insights into the evolution of a non-biological protein: importance of surface residues in protein fold optimization.
Structural insights into the evolution of a non-biological protein: importance of surface residues in protein fold optimization.
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对非生物蛋白的演变的结构见解：蛋白质折叠优化中表面残基的重要性。
DOI：
10.1371/journal.pone.0000467
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发表时间：
2007-05-23
期刊：
影响因子：
3.7
通讯作者：
Chaput JC
中科院分区：
文献类型：
--
作者：
Smith MD;Rosenow MA;Wang M;Allen JP;Szostak JW;Chaput JC
蛋白质中氨基酸取代模式的系统发育分析使许多人得出结论，大多数结构信息是由溶剂不可及的内部核心残基携带的。这一结论是基于这样的观察，即埋藏的残基通常仅容忍保守的序列变化，而表面残基允许更多样化的化学取代。这一概念现在正在改变，因为很明显，核心和表面残基在蛋白质折叠和稳定性中起着重要作用。不幸的是，识别将导致增强的稳定性的特定突变的能力仍然是一个具有挑战性的问题。在这里，我们讨论了两个突变，出现在体外选择实验，旨在提高非生物ATP结合蛋白的折叠稳定性。这些突变改变了两个溶剂可接近的残基，并显着增强蛋白质的表达，溶解性，热稳定性和配体结合亲和力。这两个突变的意义进行了研究，单独和一起，和X-射线晶体结构的亲本序列和双突变体蛋白质分别解决了2.8和1.65 μ m的分辨率限制。进化蛋白质与自然界中发现的蛋白质的比较结构分析表明，我们的非生物蛋白质进化出了许多嗜热蛋白质所共有的某些结构特征。该实验结果表明，通过体外选择的蛋白质折叠优化提供了一种可行的方法来产生许多天然存在的蛋白质的稳定变体，这些蛋白质的结构和功能难以以其他方式研究。
Phylogenetic profiling of amino acid substitution patterns in proteins has led many to conclude that most structural information is carried by interior core residues that are solvent inaccessible. This conclusion is based on the observation that buried residues generally tolerate only conserved sequence changes, while surface residues allow more diverse chemical substitutions. This notion is now changing as it has become apparent that both core and surface residues play important roles in protein folding and stability. Unfortunately, the ability to identify specific mutations that will lead to enhanced stability remains a challenging problem. Here we discuss two mutations that emerged from an in vitro selection experiment designed to improve the folding stability of a non-biological ATP binding protein. These mutations alter two solvent accessible residues, and dramatically enhance the expression, solubility, thermal stability, and ligand binding affinity of the protein. The significance of both mutations was investigated individually and together, and the X-ray crystal structures of the parent sequence and double mutant protein were solved to a resolution limit of 2.8 and 1.65 Å, respectively. Comparative structural analysis of the evolved protein to proteins found in nature reveals that our non-biological protein evolved certain structural features shared by many thermophilic proteins. This experimental result suggests that protein fold optimization by in vitro selection offers a viable approach to generating stable variants of many naturally occurring proteins whose structures and functions are otherwise difficult to study.
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影响因子：
3.5
作者：
Matsuura, T;Plückthun, A
通讯作者：
Plückthun, A
影响因子：
16.8
作者：
Lo Surdo, P;Walsh, MA;Sollazzo, M
通讯作者：
Sollazzo, M
DOI：
10.1107/s090744490200118x
发表时间：
2002-03-01
期刊：
ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY
影响因子：
--
作者：
Dauter, Z;Dauter, M;Dodson, E
通讯作者：
Dodson, E
DOI：
10.1107/s090744499900846x
发表时间：
1999-10-01
期刊：
ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY
影响因子：
--
作者：
Leslie, AGW
通讯作者：
Leslie, AGW
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K