Elucidation of the redox regulation of nitrogenase using anaerobic experimental system

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K07099
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Plant molecular biology/Plant physiology
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: nomata jiro 東京工業大学, 科学技術創成研究院, 助教 (40583216)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 鉄硫黄クラスター / チオレドキシン / シアノバクテリア

Outline of Final Research Achievements

Anabaena sp. strain PCC 7120 (A.7120) is a diazotrophic cyanobacterium, which can fix atmospheric nitrogen by utilizing nitrogenase. NifU protein plays a crucial role as a scaffold protein for the assembly of the Fe-S clusters required for the full activation of nitrogenase. Recently, we showed NifU protein is a target of thioredoxin (Trx) in A7120, and N-terminal catalytic domain of NifU(UN) was reduced by TrxM1. In this work, based on the anaerobic biochemical analysis, we showed disulfide bond formed in the C-terminal catalytic domain of NifU(UC) was reduced by TrxM1. In contrast to the UN, disulfide bond formed in UC was reduced by glutathione. Further, we studied redox regulation of NifU-like protein, NifU2. We observed that the disulfide bonds formed in the NifU2 was reduced by Trx isoforms and glutathione with different efficiency. This result indicates that Trxs may be involved in the Fe-S cluster biogenesis by NifU2.

Free Research Field

嫌気生化学