德国阿尔伯特路德维希大学Oliver Einsle和美国范安德尔研究所Juan Du研究组合作报道了一氧化二氮还原酶 (N2OR)组装机制的分子相互作用。2022年7月27日，国际知名学术期刊《自然》发表了这一成果。
他们分别报告了施氏假单胞菌 NosDFY 及其与 NosL 和 N2OR 的复合物的冷冻电镜结构。他们发现周质 NosD 蛋白含有一个 Cu+ 离子的结合位点，并在其无核苷酸状态下与 NosL 特异性相互作用，而它与 N2OR 的结合需要由 ATP 结合触发的构象变化。NosDFY 与 NosL 和 N2OR 复合的互斥结构揭示了高度复杂的铜位点的顺序金属转运和组装途径。在该途径中，NosDFY 充当机械能传感器而不是转运体。它将细胞质中的 ATP 水解与周质中 NosD 亚基的构象转变联系起来，这是 NosDFY 转换其相互作用伙伴所必需的，以便铜离子从伴侣 NosL 转移到酶 N2OR。
据悉，在过去的几十年中，土壤和工业过程中的关键臭氧消耗和温室气体N2O的排放量大幅增加。作为细菌反硝化的最后一步，在由铜依赖性一氧化二氮还原酶 (N2OR) 催化的反应中，N2O 被还原为化学惰性 N2。其独特的 [4Cu:2S] 活性位点簇 CuZ 的组装需要 ATP 结合盒（ABC）复合物 NosDFY 和膜锚定的铜伴侣 NosL。
附：英文原文
Title: Molecular interplay of an assembly machinery for nitrous oxide reductase
Author: Mller, Christoph, Zhang, Lin, Zipfel, Sara, Topitsch, Annika, Lutz, Marleen, Eckert, Johannes, Prasser, Benedikt, Chami, Mohamed, L, Wei, Du, Juan, Einsle, Oliver
Issue&Volume: 2022-07-27
Abstract: Emissions of the critical ozone-depleting and greenhouse gas nitrous oxide (N2O) from soils and industrial processes have increased considerably over the last decades1,2,3. As the final step of bacterial denitrification, N2O is reduced to chemically inert N2 (refs. 1,4) in a reaction that is catalysed by the copper-dependent nitrous oxide reductase (N2OR) (ref. 5). The assembly of its unique [4Cu:2S] active site cluster CuZ requires both the ATP-binding-cassette (ABC) complex NosDFY and the membrane-anchored copper chaperone NosL (refs. 4,6). Here we report cryo-electron microscopy structures of Pseudomonas stutzeri NosDFY and its complexes with NosL and N2OR, respectively. We find that the periplasmic NosD protein contains a binding site for a Cu+ ion and interacts specifically with NosL in its nucleotide-free state, whereas its binding to N2OR requires a conformational change that is triggered by ATP binding. Mutually exclusive structures of NosDFY in complex with NosL and with N2OR reveal a sequential metal-trafficking and assembly pathway for a highly complex copper site. Within this pathway, NosDFY acts as a mechanical energy transducer rather than as a transporter. It links ATP hydrolysis in the cytoplasm to a conformational transition of the NosD subunit in the periplasm, which is required for NosDFY to switch its interaction partner so that copper ions are handed over from the chaperone NosL to the enzyme N2OR.
DOI: 10.1038/s41586-022-05015-2
Source: https://www.nature.com/articles/s41586-022-05015-2
Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
投稿链接：http://www.nature.com/authors/submit_manuscript.html
本期文章：《自然》：Online/在线发表
