High-Resolution Crystal Structure of an Artificial (βα)8-Barrel Protein Designed from Identical Half-Barrels
High-Resolution Crystal Structure of an Artificial (βα)8-Barrel Protein Designed from Identical Half-Barrels
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DOI：
10.1021/bi802125b
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发表时间：
2009-02-17
期刊：
影响因子：
2.9
通讯作者：
Sterner, Reinhard
中科院分区：
文献类型：
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作者：
Hoecker, Birte;Lochner, Adriane;Sterner, Reinhard
大量证据表明，无处不在的(β-α)(8)桶状折叠酶是通过祖先(β-α)(4)-半桶的复制和融合而进化的。为了在实验室用模型蛋白重建这一过程，我们早些时候融合了咪唑甘油磷酸合成酶(HISF)的C端半桶HISF-C的两个副本，并逐步稳定了得到的HISF-CC构建物。我们现在通过引入两个额外的氨基酸交换进一步提高了它的稳定性和溶解性，这使得我们能够结晶得到人工(βα)(8)桶蛋白HISF-C*C。在2.1埃分辨率下对其X射线结构的分析揭示了它与野生型HISF惊人的相似之处，帮助我们理解它提高的稳定性，并为(βα)(8)桶蛋白的进化提供了进一步的见解。
Ample evidence suggests that the ubiquitous (beta alpha)(8)-barrel enzyme fold has evolved by the duplication and fusion of an ancestral (beta alpha)(4)-half-barrel. To reconstruct this process in the laboratory with a model protein, we earlier fused two copies of the C-terminal half-barrel HisF-C of imidazole glycerol phosphate synthase, (HisF) and stepwise stabilized the resulting HisF-CC construct. We now further increased its stability and Solubility by introducing two additional amino acid exchanges, which allowed us to crystallize the resulting artificial (beta alpha)(8)-barrel protein HisF-C***C. The analysis of its X-ray structure at 2.1 angstrom resolution reveals a striking similarity to wildtype HisF, helps us to understand its improved stability, and provides further insights into the evolution of (beta alpha)(8)-barrel proteins.