Department of Chemistry and Biochemistry and the Astrobiology Biogeocatalysis Research Center, Montana State University, Bozeman, Montana 59717, USA.
Annu Rev Biochem. 2012;81:429-50. doi: 10.1146/annurev-biochem-052610-094911. Epub 2012 Apr 5.
[FeFe]-hydrogenses and molybdenum (Mo)-nitrogenase are evolutionarily unrelated enzymes with unique complex iron-sulfur cofactors at their active sites. The H cluster of [FeFe]-hydrogenases and the FeMo cofactor of Mo-nitrogenase require specific maturation machinery for their proper synthesis and insertion into the structural enzymes. Recent insights reveal striking similarities in the biosynthetic pathways of these complex cofactors. For both systems, simple iron-sulfur cluster precursors are modified on assembly scaffolds by the activity of radical S-adenosylmethionine (SAM) enzymes. Radical SAM enzymes are responsible for the synthesis and insertion of the unique nonprotein ligands presumed to be key structural determinants for their respective catalytic activities. Maturation culminates in the transfer of the intact cluster assemblies to a cofactor-less structural protein recipient. Required roles for nucleotide binding and hydrolysis have been implicated in both systems, but the specific role for these requirements remain unclear. In this review, we highlight the progress on [FeFe]-hydrogenase H cluster and nitrogenase FeMo-cofactor assembly in the context of these emerging paradigms.
[FeFe]-氢化酶和钼（Mo）氮酶是进化上无关的酶，其活性位点具有独特的复杂铁硫辅因子。[FeFe]-氢化酶的 H 簇和 Mo 氮酶的 FeMo 辅因子需要特定的成熟机制来正确合成并插入结构酶中。最近的研究揭示了这些复杂辅因子生物合成途径的惊人相似之处。对于这两个系统，简单的铁硫簇前体在组装支架上通过自由基 S-腺苷甲硫氨酸（SAM）酶的活性进行修饰。自由基 SAM 酶负责合成和插入独特的非蛋白配体，这些配体被认为是各自催化活性的关键结构决定因素。成熟过程以完整簇组装体转移到无辅因子结构蛋白受体结束。核苷酸结合和水解的必需作用在这两个系统中都有涉及，但这些要求的具体作用仍不清楚。在这篇综述中，我们强调了在这些新兴范例背景下，[FeFe]-氢化酶 H 簇和氮酶 FeMo 辅因子组装的进展。
