Sirajuddin Sarah, Rosenzweig Amy C
Departments of Molecular Biosciences and of Chemistry, Northwestern University, Evanston, Illinois 60208, United States.
Biochemistry. 2015 Apr 14;54(14):2283-94. doi: 10.1021/acs.biochem.5b00198. Epub 2015 Apr 1.
Methane monooxygenases (MMOs) are enzymes that catalyze the oxidation of methane to methanol in methanotrophic bacteria. As potential targets for new gas-to-liquid methane bioconversion processes, MMOs have attracted intense attention in recent years. There are two distinct types of MMO, a soluble, cytoplasmic MMO (sMMO) and a membrane-bound, particulate MMO (pMMO). Both oxidize methane at metal centers within a complex, multisubunit scaffold, but the structures, active sites, and chemical mechanisms are completely different. This Current Topic review article focuses on the overall architectures, active site structures, substrate reactivities, protein-protein interactions, and chemical mechanisms of both MMOs, with an emphasis on fundamental aspects. In addition, recent advances, including new details of interactions between the sMMO components, characterization of sMMO intermediates, and progress toward understanding the pMMO metal centers are highlighted. The work summarized here provides a guide for those interested in exploiting MMOs for biotechnological applications.
甲烷单加氧酶（MMOs）是一类能在甲烷营养型细菌中将甲烷氧化为甲醇的酶。作为新型气制液甲烷生物转化过程的潜在靶点，近年来MMOs受到了广泛关注。MMOs有两种不同类型，即可溶性胞质MMO（sMMO）和膜结合颗粒MMO（pMMO）。二者均在一个复杂的多亚基支架内的金属中心处氧化甲烷，但它们的结构、活性位点和化学机制完全不同。这篇“当前主题”综述文章重点关注了两种MMOs的整体结构、活性位点结构、底物反应性、蛋白质-蛋白质相互作用及化学机制，尤其侧重于基础方面。此外，还强调了近期的进展，包括sMMO各组分间相互作用的新细节、sMMO中间体的表征以及在理解pMMO金属中心方面取得的进展。本文总结的工作为那些有兴趣利用MMOs进行生物技术应用的人提供了指导。
