Crystal structure of unligated guanylate kinase from yeast reveals GMP-induced conformational changes
Crystal structure of unligated guanylate kinase from yeast reveals GMP-induced conformational changes
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DOI：
10.1006/jmbi.2000.4427
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发表时间：
2001-03-16
影响因子：
5.6
通讯作者：
Ji, XH
中科院分区：
文献类型：
--
作者：
Blaszczyk, J;Li, Y;Ji, XH
本文报道了来自酵母（Saccharomycescerevisiae）的鸟苷酸激酶（GK）的非连接态（apo-GK）和与GMP复合态（GK CMF）的晶体结构。apo-GK的结构用多波长异常衍射数据求解，并在2.3埃分辨率下精确到0.164的X因子（R-free = 0.199）。GK（.）使用具有乙酰化的N末端的GK的晶体结构作为搜索模型来确定GMP，并在1.9埃下精确到0.156的R因子（无R = 0.245）。GK属于核苷单磷酸（NMP）激酶家族，催化从ATP到GMP的可逆磷酰基转移。与其他NMP激酶一样，GK由三个动态结构域组成：CORE、LID和NMP结合结构域。通过比较apo-CK和GK的结构，揭示了GMP结合结构域的剧烈运动和LID结构域的较小但显著的运动。GMP。apo-GK具有比GK GMP复合物开放得多的构象。使用程序DynDom对结构域运动的系统分析表明，GMP结合结构域的大的运动涉及围绕与螺旋3近似平行的有效铰链轴的旋转，所述螺旋3连接GMP结合结构域和CORE结构域。螺旋3的C-末端部分连接到CORE结构域，在GK（.）中具有显著更高的温度因子。GMP比apo-CK，表明这些残基变得更加移动的CMP结合。结果表明螺旋3在结构域运动中起重要作用。与GMP结合结构域不同，GMP结合结构域在GMP结合时向酶的活性中心移动，LID结构域远离活性中心移动，使推测的ATP结合位点更加开放。因此，LID结构域的移动可以促进MgATP的结合。重组GK（.）CMP复合物与天然GK（.）GMP复合物，表明N-末端乙酰化对GK的三维结构没有显著影响。(C)北京：科学出版社.
The crystal structure of guanylate kinase (GK) from yeast (Saccharomyces cerevisiae) with a non-acetylated N terminus has been determined in its unligated form (apo-GK) as well as in complex with GMP (GK CMF). The structure of apo-GK was solved with multiwavelength anomalous diffraction data and refined to an X-factor of 0.164 (R-free = 0.199) at 2.3 Angstrom resolution. The structure of GK (.) GMP was determined using the crystal structure of GK with an acetylated N terminus as the search model and refined to an R-factor of 0.156 (R-free = 0.245) at 1.9 Angstrom. GK belongs to the family of nucleoside monophosphate (NMP) kinases and catalyzes the reversible phosphoryl transfer from ATP to GMP. Like other NMP kinases, GK consists of three dynamic domains: the CORE, LID, and NMP-binding domains. Dramatic movements of the GMP-binding domain and smaller but significant movements of the LID domain have been revealed by comparing the structures of apo-CK and GK (.) GMP. apo-GK has a much more open conformation than the GK GMP complex. Systematic analysis of the domain movements using the program DynDom shows that the large movements of the GMP-binding domain involve a rotation around an effective hinge axis approximately parallel with helix 3, which connects the GMP-binding and CORE domains. The C-terminal portion of helix 3, which connects to the CORE domain, has strikingly higher temperature factors in GK (.) GMP than in apo-CK, indicating that these residues become more mobile upon CMP binding. The results suggest that helix 3 plays an important role in domain movement. Unlike the GMP-binding domain, which moves toward the active center of the enzyme upon GMP binding, the LID domain moves away from the active center and makes the presumed ATP-binding site more open. Therefore, the LID domain movement may facilitate the binding of MgATP. The structure of the recombinant GK (.) CMP complex superimposes very well with that of the native GK (.) GMP complex, indicating that N-terminal acetylation does not have significant impact on the three-dimensional structure of GK. (C) 2001 Academic Press.