Elucidation of thioredoxin mediated redox-regulation of nitrogenase activity in photosynthetic organisms

2014 Fiscal Year Final Research Report

• Project/Area Number: 24770040
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Plant molecular biology/Plant physiology
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: NOMATA Jiro 東京工業大学, 資源化学研究所, 助教 (40583216)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: レドックス / 金属中心 / シアノバクテリア / 窒素固定 / プロテオミクス

Outline of Final Research Achievements

Anabaena sp. strain PCC 7120 (A.7120) is a diazotrophic cyanobacterium, which can fix atmospheric nitrogen by utilizing the solar energy. Thioredoxin (Trx) is a class of small redox proteins known to play a role in many important biological processes. Recently, NifU protein was captured in the A.7120 by using the proteomics-method named “Thioredoxin affinity chromatography” to comprehensively isolate TrxM target proteins. NifU protein plays a crucial role as a scaffold protein for the assembly of the Fe-S clusters required for the full activation of Fe-protein and MoFe-protein of nitrogenase. In this work, based on the biochemical analysis, we showed disulfide bond(s) formed in the N-terminal catalytic domain in NifU protein was reduced by Trx M. Further, we observed that the scaffold activity of the catalytic domain of NifU is enhanced in the presence of Trx-system, suggesting that TrxM is involved in the Fe-S cluster biogenesis by NifU.

Free Research Field

レドックス