High-resolution crystal structure of copper amine oxidase from Arthrobacter globiformis: assignment of bound diatomic molecules as O2
High-resolution crystal structure of copper amine oxidase from Arthrobacter globiformis: assignment of bound diatomic molecules as O2
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球状节杆菌铜胺氧化酶的高分辨率晶体结构：将结合的双原子分子指定为 O2
DOI：
10.1107/s0907444913023196
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Okajima T.
中科院分区：
文献类型：
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作者：
Murakawa T;Hayashi H;Sunami T;Kurihara K;Tamada T;Kuroki R;Suzuki M;Tanizawa K;Okajima T.
使用低分子量聚乙二醇（LMW PEG；平均分子量~200）作为冷冻保护剂，以 1.08 Å 的分辨率测定了球状节杆菌的铜胺氧化酶的晶体结构。最终的晶体学 R 因子和 Rfree 分别为 13.0 和 15.0%。发现几个 LMW PEG 分子占据了蛋白质内部的空腔，包括活性位点，这导致整体 B 因子显着减少，从而导致单体分子量为 ∼70 000 的相对较大蛋白质的亚原子分辨率结构。大约 40% 的假定 H 原子在 Fo – Fc 差异图中观察到清晰的电子密度。还鉴定出许多残基的多个次要构象异构体。在活性位点评估了各向异性位移波动，该活性位点包含翻译后衍生的醌辅因子和铜原子。此外，双原子分子（最有可能是分子氧）与蛋白质结合，其中一个分子位于先前被提议作为双氧底物从二聚体界面的中心腔到活性位点的进入路径的区域中。
The crystal structure of a copper amine oxidase from Arthrobacter globiformis was determined at 1.08 Å resolution with the use of low-molecular-weight polyethylene glycol (LMW PEG; average molecular weight ∼200) as a cryoprotectant. The final crystallographic R factor and Rfree were 13.0 and 15.0%, respectively. Several molecules of LMW PEG were found to occupy cavities in the protein interior, including the active site, which resulted in a marked reduction in the overall B factor and consequently led to a subatomic resolution structure for a relatively large protein with a monomer molecular weight of ∼70 000. About 40% of the presumed H atoms were observed as clear electron densities in the Fo − Fc difference map. Multiple minor conformers were also identified for many residues. Anisotropic displacement fluctuations were evaluated in the active site, which contains a post-translationally derived quinone cofactor and a Cu atom. Furthermore, diatomic molecules, most likely to be molecular oxygen, are bound to the protein, one of which is located in a region that had previously been proposed as an entry route for the dioxygen substrate from the central cavity of the dimer interface to the active site.