Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan.
J Biochem. 2013 Sep;154(3):233-6. doi: 10.1093/jb/mvt070. Epub 2013 Aug 1.
We have determined the x-ray crystal structure of L-lysine ε-oxidase from Marinomonas mediterranea in its native and L-lysine-complex forms at 1.94- and 1.99-Å resolution, respectively. In the native enzyme, electron densities clearly indicate the presence of cysteine tryptophylquinone (CTQ) previously identified in quinohemoprotein amine dehydrogenase. In the L-lysine-complex, an electron density corresponding to the bound L-lysine shows that its ε-amino group is attached to the C6 carbonyl group of CTQ, suggesting the formation of a Schiff-base intermediate. Collectively, the present crystal structure provides the first example of an enzyme employing a tryptophylquinone cofactor in an amine oxidase.
我们已经确定了来自 Marinomonas mediterranea 的 L-赖氨酸 ε-氧化酶在其天然形式和 L-赖氨酸复合物形式下的 X 射线晶体结构，分辨率分别为 1.94 和 1.99Å。在天然酶中，电子密度清楚地表明存在半胱氨酸色氨酸醌（CTQ），这在醌核苷酸胺脱氢酶中已经被鉴定。在 L-赖氨酸复合物中，与结合的 L-赖氨酸相对应的电子密度表明其 ε-氨基与 CTQ 的 C6 羰基相连，表明形成了希夫碱中间产物。总的来说，目前的晶体结构提供了第一个使用色氨酸醌辅因子的胺氧化酶的例子。
