X-ray structure of pyruvate formate-lyase in complex with pyruvate and CoA - How the enzyme uses the Cys-418 thiyl radical for pyruvate cleavage
X-ray structure of pyruvate formate-lyase in complex with pyruvate and CoA - How the enzyme uses the Cys-418 thiyl radical for pyruvate cleavage
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DOI：
10.1074/jbc.m205821200
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发表时间：
2002-10-18
影响因子：
4.8
通讯作者：
Kabsch, W
中科院分区：
文献类型：
--
作者：
Becker, A;Kabsch, W
甘氨酰自由基酶丙酮酸甲酸裂解酶(PFL)由丙酮酸和辅酶A合成乙酰辅酶A和甲酸盐。利用非自由基形式的PFL与其两种底物形成的络合物的晶体结构，我们捕获了丙酮酸裂解之前的时刻。该结构揭示了活性部位如何对准丙酮酸的剪切键进行自由基攻击，防止丙酮酸的非自由基副反应，并限制自由基迁移。结构显示CoA在等待丙酮酸裂解的SYN构象中。在不影响辅酶A的腺嘌呤结合方式的情况下，辅酶A的硫醇转变为反构象，可以拾取丙酮酸裂解产生的乙酰基。
The glycyl radical enzyme pyruvate formate-lyase (PFL) synthesizes acetyl-CoA and formate from pyruvate and CoA. With the crystal structure of the non-radical form of PFL in complex with its two substrates, we have trapped the moment prior to pyruvate cleavage. The structure reveals how the active site aligns the scissile bond of pyruvate for radical attack, prevents non-radical side reactions of the pyruvate, and confines radical migration. The structure shows CoA in a syn conformation awaiting pyruvate cleavage. By changing to an anti conformation, without affecting the adenine binding mode of CoA, the thiol of CoA could pick up the acetyl group resulting from pyruvate cleavage.