Crystal structure at 2.5 Å resolution of zinc-substituted copper amine oxidase of Hansenula polymorpha expressed in Escherichia coli
Crystal structure at 2.5 Å resolution of zinc-substituted copper amine oxidase of Hansenula polymorpha expressed in Escherichia coli
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DOI：
10.1021/bi000639f
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发表时间：
2000-08-15
期刊：
影响因子：
2.9
通讯作者：
Mathews, FS
中科院分区：
文献类型：
--
作者：
Chen, ZW;Schwartz, B;Mathews, FS
铜胺氧化酶（CAO）利用分子氧作为末端电子受体催化伯胺的双电子氧化成醛。为了完成这种转化，CAO利用两种辅因子：单核铜和独特的氧化还原辅因子，2，4，5-三羟基苯丙氨酸醌（TPQ或TOPA醌）。TPQ是通过蛋白质本身内特定酪氨酸残基的翻译后修饰而衍生的。在这项研究中，来自Hansenulla polymorpha的胺氧化酶的结构已经被解决到2.5埃分辨率，其中前体酪氨酸未被加工成TPQ，并且铜位点被锌占据。值得注意的是，前体酪氨酸直接配位金属，从而提供了最接近的类似物的中间体在TPQ生产日期。除了这一结果，重排的其他活性位点残基（相对于成熟的酶）提出参与分子氧的结合可能会揭示如何CAO有效地利用其活性位点进行辅因子的形成和催化。
Copper amine oxidases (CAOs) catalyze the two-electron oxidation of primary amines to aldehydes, utilizing molecular oxygen as a terminal electron acceptor. To accomplish this transformation, CAOs utilize two cofactors: a mononuclear copper, and a unique redox cofactor, 2,4,5-trihydroxyphenylalanine quinone (TPQ or TOPA quinone). TPQ is derived via posttranslational modification of a specific tyrosine residue within the protein itself. In this study, the structure of an amine oxidase from Hansenulla polymorpha has been solved to 2.5 Angstrom resolution, in which the precursor tyrosine is unprocessed to TPQ, and the copper site is occupied by zinc. Significantly, the precursor tyrosine directly ligands the metal, thus providing the closest analogue to date of an intermediate in TPQ production. Besides this result, the rearrangement of other active site residues (relative to the mature enzyme) proposed to be involved in the binding of molecular oxygen may shed light on how CAOs efficiently use their active site to carry out both cofactor formation and catalysis.