Reissmann Stefanie, Hochleitner Elisabeth, Wang Haofan, Paschos Athanasios, Lottspeich Friedrich, Glass Richard S, Böck August
Department Biologie I, Mikrobiologie, University of Munich, Maria-Ward-Strasse 1a, D-80638 Munich, Germany.
Science. 2003 Feb 14;299(5609):1067-70. doi: 10.1126/science.1080972.
NiFe-hydrogenases have an Ni-Fe site in which the iron has one CO and two CN groups as ligands. Synthesis of the CN ligands requires the activity of two hydrogenase maturation proteins: HypF and HypE. HypF is a carbamoyltransferase that transfers the carbamoyl moiety of carbamoyladenylate to the COOH-terminal cysteine of HypE and thus forms an enzyme-thiocarbamate. HypE dehydrates the S-carbamoyl moiety in an adenosine triphosphate-dependent process to yield the enzyme thiocyanate. Chemical model reactions corroborate the feasibility of this unprecedented biosynthetic route and show that thiocyanates can donate CN to iron. This finding underscores a striking parallel between biochemistry and organometallic chemistry in the formation of an iron-cyano complex.
镍铁氢化酶有一个镍铁位点，其中铁有一个一氧化碳和两个氰基作为配体。氰基配体的合成需要两种氢化酶成熟蛋白的活性：HypF和HypE。HypF是一种氨甲酰基转移酶，它将氨甲酰腺苷酸的氨甲酰部分转移到HypE的羧基末端半胱氨酸上，从而形成一种酶-硫代氨基甲酸盐。HypE在一个依赖三磷酸腺苷的过程中使S-氨甲酰部分脱水，生成酶硫氰酸盐。化学模型反应证实了这条前所未有的生物合成途径的可行性，并表明硫氰酸盐可以向铁提供氰基。这一发现突出了在形成铁氰配合物过程中生物化学与有机金属化学之间惊人的相似性。
