ClpS2 is a small protein under development as a probe for selectively recognizing N‐terminal amino acids of N‐degron peptide fragments. To understand the structural basis of ClpS2 specificity for an N‐terminal amino acid, all atom molecular dynamics (MD) simulations were conducted using the sequence of a bench‐stable mutant of ClpS2, called PROSS. We predicted that a single amino acid leucine to asparagine substitution would switch the specificity of PROSS ClpS2 to an N‐terminal tyrosine over the preferred phenylalanine. Experimental validation of the mutant using a fluorescent yeast‐display assay showed an increase in tyrosine binding over phenylalanine, in support of the proposed hypothesis.

中文翻译：

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单个氨基酸取代改变ClpS2结合特异性。

ClpS2是一种小的蛋白质，正在开发中，可以选择性识别N-degron肽片段的N-末端氨基酸。为了了解ClpS2对N末端氨基酸的特异性的结构基础，所有原子分子动力学（MD）模拟均使用称为PROSS的长凳稳定ClpS2突变体的序列进行。我们预测，将单个氨基酸亮氨酸替换为天冬酰胺会比首选的苯丙氨酸将PROSS ClpS2的特异性切换为N末端的酪氨酸。通过荧光酵母展示试验对突变体进行的实验验证表明，酪氨酸与苯丙氨酸的结合增加，以支持所提出的假设。