Suess Daniel L M, Pham Cindy C, Bürstel Ingmar, Swartz James R, Cramer Stephen P, Britt R David
Department of Chemistry, University of California, Davis , Davis, California 95616, United States.
J Am Chem Soc. 2016 Feb 3;138(4):1146-9. doi: 10.1021/jacs.5b12512. Epub 2016 Jan 20.
Three maturase enzymes-HydE, HydF, and HydG-synthesize and insert the organometallic component of the [FeFe]-hydrogenase active site (the H-cluster). HydG generates the first organometallic intermediates in this process, ultimately producing an [Fe(CO)2(CN)] complex. A limitation in understanding the mechanism by which this complex forms has been uncertainty regarding the precise metallocluster composition of HydG that comprises active enzyme. We herein show that the HydG auxiliary cluster must bind both l-cysteine and a dangler Fe in order to generate the [Fe(CO)2(CN)] product. These findings support a mechanistic framework in which a (Cys)Fe(CO)2(CN) species is a key intermediate in H-cluster maturation.
三种成熟酶——HydE、HydF和HydG——合成并插入[FeFe]氢化酶活性位点（H簇）的有机金属成分。HydG在此过程中产生第一种有机金属中间体，最终生成一种[Fe(CO)2(CN)]配合物。在理解该配合物形成机制方面的一个限制是，对于构成活性酶的HydG的确切金属簇组成存在不确定性。我们在此表明，HydG辅助簇必须同时结合l-半胱氨酸和一个游离铁，才能生成[Fe(CO)2(CN)]产物。这些发现支持了一个机制框架，其中(Cys)Fe(CO)2(CN)物种是H簇成熟过程中的关键中间体。
