The triosephosphate isomerase-barrel structure is shared by 10% of known enzymes, making it an attractive system to investigate enzyme design. While most dihedral angles in proteins occupy specific regions of the Ramachandran plot, residues such as Lys13 in triosephosphate isomerase adopt an energetically unfavorable conformation. Allen et al. report the effects of mutating nearby Asn11 to Ala, revealing the loss of observable enzyme activity. Molecular dynamics simulations suggest the unfavorable Lys13 conformation is not present in the mutant, indicating that this unfavorable conformation – supported by a nearby residue – is important for enzyme activity. The results may help guide the design of enzymes requiring specific interactions to position residues within the active site. DOI: 10.1002/bip.23525

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10% 的已知酶都具有丙糖磷酸异构酶桶结构，这使其成为研究酶设计的一个有吸引力的系统。虽然蛋白质中的大多数二面角占据 Ramachandran 图的特定区域，但磷酸丙糖异构酶中的 Lys13 等残基采用能量不利的构象。艾伦等人。报告将附近的 Asn11 突变为 Ala 的影响，揭示了可观察到的酶活性的丧失。分子动力学模拟表明突变体中不存在不利的 Lys13 构象，表明这种不利的构象——由附近的残基支持——对酶活性很重要。结果可能有助于指导需要特定相互作用以将残基定位在活性位点内的酶的设计。DOI: 10.1002/bip.23525