Crystal structure of the activated insulin receptor tyrosine kinase in complex with peptide substrate and ATP analog
Crystal structure of the activated insulin receptor tyrosine kinase in complex with peptide substrate and ATP analog
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DOI：
10.1093/emboj/16.18.5572
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发表时间：
1997-09-15
期刊：
影响因子：
11.4
通讯作者：
Hubbard, SR
中科院分区：
文献类型：
--
作者：
Hubbard, SR
在1.9埃分辨率下，测定了胰岛素受体酪氨酸激酶的磷酸化活化形式与多肽底物和ATP类似物的络合物的晶体结构。当激活环中的Tyr1158、Tyr1162和Tyr1163发生自动磷酸化时，激酶的激活环(A环)经历了主要的构象变化，导致ATP和蛋白质底物不受限制地访问激酶活性部位。磷酸化Tyr1163(PTyr1163)是稳定三磷酸化A-环构象的关键磷酸酪氨酸，而pTyr1158完全暴露在溶剂中，这表明可以与下游信号蛋白相互作用。含有YMXM的多肽底物以反平行的短链形式结合到A-环的C-末端，蛋氨酸侧链占据了该激酶C-末端叶上的两个疏水口袋。因此，该结构揭示了通过自磷酸化激活胰岛素受体的分子基础，并为深入了解酪氨酸激酶底物的特异性和磷酸转移的机制提供了线索。
The crystal structure of the phosphorylated, activated form of the insulin receptor tyrosine kinase in complex with a peptide substrate and an ATP analog has been determined at 1.9 Angstrom resolution. The activation loop (A-loop) of the kinase undergoes a major conformational change upon autophosphorylation of Tyr1158, Tyr1162 and Tyr1163 within the loop, resulting in unrestricted access of ATP and protein substrates to the kinase active site. Phosphorylated Tyr1163 (pTyr1163) is the key phosphotyrosine in stabilizing the conformation of the tris-phosphorylated A-loop, whereas pTyr1158 is completely solvent-exposed, suggesting an availability for interaction with downstream signaling proteins. The YMXM-containing peptide substrate binds as a short anti-parallel beta-strand to the C-terminal end of the A-loop, with the methionine side chains occupying two hydrophobic pockets on the C-terminal lobe of the kinase. The structure thus reveals the molecular basis for insulin receptor activation via autophosphorylation, and provides insights into tyrosine kinase substrate specificity and the mechanism of phosphotransfer.