在行为:磷酸化的结构从Lactococcus beta-phosphoglucomutase lactis。
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张Lahiri SD, G, Dunaway-Mariano D,艾伦KN
在行为:磷酸化的结构从Lactococcus beta-phosphoglucomutase lactis。
生物化学。2002年7月2;41 (26):8351 - 9。
- PubMed ID
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12081483 (在PubMed]
- 文摘
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Phosphoglucomutases催化葡萄糖的互变现象1-phosphate和葡萄糖6-phosphate,反应各细胞能量代谢的中心,在细菌细胞细胞壁多糖的合成。两类phosphoglucomutases (alpha-PGM和beta-PGM)是著名的基础上他们的特异性α-和beta-glucose-1-phosphate。beta-PGM属于haloacid dehalogenase(已经)总科,其中包括肌质Ca(2 +)腺苷三磷酸酶,phosphomannomutase和磷酸丝氨酸磷酸酶。beta-PGM是不寻常的家庭成员之间在共同phosphoenzyme中间存在一个稳定的基态复杂的酶。我们在此报告,第一次beta-PGM和第一个视图的三维结构的真正phosphoenzyme中间的总科。Mg (II)的晶体结构复杂的磷酸化beta-phosphoglucomutase (beta-PGM) Lactococcus lactis 2.3决心解决了多波长反常衍射(疯狂)逐步硒代蛋氨酸,和精制(结晶)= 0.24和R(免费)= 0.28。beta-PGM位于核心之间的活性部位和帽域和溶剂自由访问。6半径内残留的磷酸化Asp8包括Asp10 Thr16, Ser114, Lys145 Glu169, Asp170。代数余子式镁(2 +)与八面体配位几何Asp8羧酸酯侧链的协调,Glu169, Asp170,骨干的Asp10连同一个氧羰基氧Asp8-phosphoryl组和一个水配体。Asp8 phosphoaspartyl残渣的磷酸基,与Ser114和Lys145的侧链。 The absence of a base residue near the aspartyl phosphate group accounts for the persistence of the phosphorylated enzyme under physiological conditions. Substrate docking shows that glucose-6-P can bind to the active site of phosphorylated beta-PGM in such a way as to position the C(1)OH near the phosphoryl group of the phosphorylated Asp8 and the C(6) phosphoryl group near the carboxylate group of Asp10. This result suggests a novel two-base mechanism for phosphoryl group transfer in a phosphorylated sugar.