amidotransferase家族的酶:氨分子机器的生产和交付。

文章的细节

引用

复制到剪贴板

Raushel调频,Thoden JB,霍尔顿嗯

amidotransferase家族的酶:氨分子机器的生产和交付。

生物化学。1999年6月22日,38 (25):7891 - 9。doi: 10.1021 / bi990871p。

PubMed ID

10387030 (在PubMed

]

文摘

amidotransferase家族的酶利用氨来源于谷氨酰胺的水解随后催化的化学反应相同的酶。氨的中间不分离到化学转换解决方案。一个良好的例子显示的结构和机制提供了这类酶[氨基甲酰磷酸合成酶(CPS)。[氨基甲酰磷酸合成酶是孤立的从大肠杆菌heterodimeric蛋白质。小的两个亚基催化谷氨酸谷氨酰胺的水解和氨。大亚基催化的形成[氨基甲酰磷酸使用2摩尔的ATP,碳酸氢氨。动能调查导致了这种酶的化学机制提出要求羧基磷酸盐、氨、氨基甲酸酯活动主管反应中间体。CPS的三维x射线晶体结构局部的位置三个活跃的网站。氨基端内的核苷酸结合位点的一半所需的大亚基磷酸化的碳酸氢盐和随后的氨基甲酸酯的形成。c端域内的核苷酸结合位点的大亚基氨基甲酸催化磷酸化的最终产品,[氨基甲酰磷酸。 The three active sites within the heterodimeric protein are separated from one another by about 45 A. The ammonia produced within the active site of the small subunit is the substrate for reaction with the carboxy phosphate intermediate that is formed in the active site found within the N-terminal half of the large subunit of CPS. Since the ammonia does not dissociate from the protein prior to its reaction with carboxy phosphate, this intermediate must therefore diffuse through a molecular tunnel that connects these two sites with one another. Similarly, the carbamate intermediate, initially formed at the active site within the N-terminal half of the large subunit, is the substrate for phosphorylation by the ATP bound to the active site located in the C-terminal half of the large subunit. A molecular passageway has been identified by crystallographic methods that apparently facilitates diffusion between these two active sites within the large subunit of CPS. Synchronization of the chemical transformations is controlled by structural perturbations among the three active sites. Molecular tunnels between distant active sites have also been identified in tryptophan synthase and glutamine phosphoribosyl pyrophosphate amidotransferase and are likely architectural features in an expanding list of enzymes.

DrugBank数据引用了这篇文章

药物靶点

药物	目标	类	生物	药理作用	行动
谷酰胺	Amidophosphoribosyltransferase	蛋白质	人类	未知的	底物	细节