Investigating the mechanism of ADP-forming acetyl-CoA synthetase from the protozoan parasite Entamoeba histolytica.
Investigating the mechanism of ADP-forming acetyl-CoA synthetase from the protozoan parasite Entamoeba histolytica.
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研究原生动物寄生虫溶组织内阿米巴形成 ADP 的乙酰辅酶 A 合成酶的机制。
DOI：
10.1002/1873-3468.12573
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发表时间：
2017
期刊：
影响因子：
3.5
通讯作者：
Ingram-Smith,Cheryl
中科院分区：
文献类型：
--
作者：
Jones,CherylP;Khan,Kirin;Ingram-Smith,Cheryl
ADP形成乙酰辅酶a合成酶（ACD）催化乙酰辅酶a与乙酸酯的相互转化。相关的琥珀酰辅酶a合成酶遵循涉及单个磷酸酶的三步机制，但提出了一个涉及两个磷酸酶中间体的新的四步机制。对内阿米巴acd的酶变体进行了表征，其中两个磷酸化的His残基被单独改变，表明只有His252对酶活性是必需的。对两个被提出与磷酸组氨酸环相互作用的残基的变异分析表明，在活性位点的不同部分之间摆动的机制与单一磷酸酶中间体一致。我们的研究结果表明，具有不同亚基结构的ACDs可能采用略微不同的机制来桥接活性位点I和II之间的跨度。
ADP‐forming acetyl‐CoA synthetase (ACD) catalyzes the interconversion of acetyl‐CoA and acetate. The related succinyl‐CoA synthetase follows a three‐step mechanism involving a single phosphoenzyme, but a novel four‐step mechanism with two phosphoenzyme intermediates was proposed forPyrococcusACD. Characterization of enzyme variants ofEntamoebaACD in which the two proposed phosphorylated His residues were individually altered revealed that only His252 is essential for enzymatic activity. Analysis of variants altered at two residues proposed to interact with the phosphohistidine loop that swings between distinct parts of the active site are consistent with a mechanism involving a single phosphoenzyme intermediate. Our results suggest ACDs with different subunit structures may employ slightly different mechanisms to bridge the span between active sites I and II.