Anthranilate synthase of Neurospora crassa: reaction and labeling with glutamine analogs.
Anthranilate synthase of Neurospora crassa: reaction and labeling with glutamine analogs.
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粗糙脉孢菌的邻氨基苯甲酸合酶：用谷氨酰胺类似物进行反应和标记。
DOI：
10.1016/0003-9861(82)90366-6
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发表时间：
1982
影响因子：
3.9
通讯作者：
DeMoss,JA
中科院分区：
文献类型：
--
作者：
Paukert,JL;Henkin,J;KeeseyJr,J;DeMoss,JA
来自粗糙脉孢菌的多功能酶复合物邻氨基苯甲酸合酶在暴露于反应性谷氨酰胺类似物DON和阿扎胞苷时不可逆地失去其谷氨酰胺依赖性邻氨基苯甲酸合酶活性。失活取决于底物分支酸盐的存在，由辅因子Mg+2增强，并由谷氨酰胺拮抗。失活与[14 C]DON掺入到蛋白质中具有定位于复合物的β亚基（Mr84，000）的修饰的相关性良好，直接证明β亚基为谷氨酰胺依赖性邻氨基苯甲酸合酶反应提供谷氨酰胺结合位点。氨依赖性邻氨基苯甲酸合酶活性损失较慢且范围较小，表明α亚基对氨依赖性邻氨基苯甲酸合酶活性的最大表达也取决于与β亚基的活性谷氨酰胺转移酶结构域的相互作用。
The multifunctional enzyme complex, anthranilate synthase fromNeurospora crassa, irreversibly loses its glutamine-dependent anthranilate synthase activity on exposure to the reactive glutamine analogs DON and azaserine. Inactivation depends on the presence of the substrate chorismate, is enhanced by the cofactor Mg+2, and is antagonized by glutamine. Inactivation correlates well with the incorporation of [14C]DON into the protein with modification localized to the β subunit (Mr84,000) of the complex, demonstrating directly that the β subunit provides the glutamine binding site for the glutamine-dependent anthranilate synthase reaction. The slower and less extensive loss of ammonia-dependent anthranilate synthase activity indicates that maximum expression of the ammonia-dependent anthranilate synthase activity by the α subunit also depends on the interaction with an active glutamine amidotransferase domain of the β subunit.