Ishibashi Yumi, Matsushima Natsumi, Ito Tomokazu, Hemmi Hisashi
Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan.
Biosci Biotechnol Biochem. 2022 Jan 24;86(2):246-253. doi: 10.1093/bbb/zbab205.
Nudix hydrolases typically catalyze the hydrolysis of nucleoside diphosphate linked to moiety X and yield nucleoside monophosphate and X-phosphate, while some of them hydrolyze a terminal diphosphate group of non-nucleosidic compounds and convert it into a phosphate group. Although the number of Nudix hydrolases is usually limited in archaea comparing with those in bacteria and eukaryotes, the physiological functions of most archaeal Nudix hydrolases remain unknown. In this study, a Nudix hydrolase family protein, MM_2582, from the methanogenic archaeon Methanosarcina mazei was recombinantly expressed in Escherichia coli, purified, and characterized. This recombinant protein shows higher hydrolase activity toward isopentenyl diphosphate and short-chain prenyl diphosphates than that toward nucleosidic compounds. Kinetic studies demonstrated that the archaeal enzyme prefers isopentenyl diphosphate and dimethylallyl diphosphate, which suggests its role in the biosynthesis of prenylated flavin mononucleotide, a recently discovered coenzyme that is required, for example, in the archaea-specific modified mevalonate pathway.
Nudix水解酶通常催化与X部分相连的核苷二磷酸的水解，生成核苷一磷酸和X-磷酸，而其中一些水解非核苷化合物的末端二磷酸基团并将其转化为磷酸基团。尽管与细菌和真核生物相比，古菌中Nudix水解酶的数量通常有限，但大多数古菌Nudix水解酶的生理功能仍然未知。在本研究中，来自产甲烷古菌马氏甲烷八叠球菌的一种Nudix水解酶家族蛋白MM_2582在大肠杆菌中进行了重组表达、纯化和表征。该重组蛋白对异戊烯基二磷酸和短链异戊二烯基二磷酸的水解酶活性高于对核苷化合物的活性。动力学研究表明，该古菌酶更喜欢异戊烯基二磷酸和二甲基烯丙基二磷酸，这表明其在异戊烯基化黄素单核苷酸生物合成中的作用，异戊烯基化黄素单核苷酸是一种最近发现的辅酶，例如在古菌特异性的甲羟戊酸途径中是必需的。
