High-resolution structure of proteinase K cocrystallized with digalacturonic acid.
High-resolution structure of proteinase K cocrystallized with digalacturonic acid.
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蛋白酶 K 与二半乳糖醛酸共结晶的高分辨率结构。
DOI：
10.1107/s1744309109002218
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
McPherson,Alexander
中科院分区：
文献类型：
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作者：
Larson,StevenB;Day,JohnS;Nguyen,Chieugiang;Cudney,Robert;McPherson,Alexander
蛋白酶K是一种类似枯草菌素的真菌蛋白酶，从含有双半乳糖醛酸（DGA）的小分子混合物中结晶出来。晶体结构的分辨率为1.32 Å， R因子为0.158。最终的模型除了含有蛋白质外，还含有2个钙离子、379个水分子、1个DGA分子和1个部分占据的HEPES分子。DGA分子有一个糖块精确地分布在晶体双轴上；第二个环没有被观察到。DGA分子通过涉及Ser150和水分子的氢键网络跨双轴与两个蛋白质分子结合。其中一个钙离子位点以前没有报道过。这项研究进一步说明了小分子通过形成分子间晶格相互作用的能力参与大分子的结晶。
Proteinase K, a subtilisin-like fungal protease, was crystallized from a cocktail of small molecules containing digalacturonic acid (DGA). The crystal structure was determined to 1.32 Å resolution and refined to an R factor of 0.158. The final model contained, beside the protein, two calcium ions, 379 water molecules, a molecule of DGA and a partially occupied HEPES molecule. The DGA molecule has one sugar moiety disposed exactly on a crystallographic twofold axis; the second ring was not observed. The DGA molecule is bound to two protein molecules across the twofold axis through hydrogen-bonding networks involving Ser150 and water molecules. One of the calcium-ion sites has not been reported previously. This study further illustrates the involvement of small molecules in the crystallization of macromolecules through their ability to form intermolecular lattice interactions.