7QYC

As isolated MSOX movie series dataset 20 (8 MGy) of the copper nitrite reductase from Bradyrhizobium sp. ORS 375 (two-domain)

7QYC の概要

• エントリーDOI: 10.2210/pdb7qyc/pdb
• 分子名称: Copper-containing nitrite reductase, SULFATE ION, COPPER (II) ION, ... (5 entities in total)
• 機能のキーワード: nitrite reductase, copper nitrite reductase, copper-containing nitrite reductase, brnir, br2dnir, as isolated, msox, oxidoreductase
• 由来する生物種: Bradyrhizobium sp. ORS 375
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 39371.93

構造登録者

Rose, S.L.,Baba, S.,Okumura, H.,Antonyuk, S.V.,Sasaki, D.,Tosha, T.,Kumasaka, T.,Eady, R.R.,Yamamoto, M.,Hasnain, S.S. (登録日: 2022-01-27, 公開日: 2022-08-03, 最終更新日: 2024-01-31)

主引用文献

Rose, S.L.,Baba, S.,Okumura, H.,Antonyuk, S.V.,Sasaki, D.,Hedison, T.M.,Shanmugam, M.,Heyes, D.J.,Scrutton, N.S.,Kumasaka, T.,Tosha, T.,Eady, R.R.,Yamamoto, M.,Hasnain, S.S.
Single crystal spectroscopy and multiple structures from one crystal (MSOX) define catalysis in copper nitrite reductases.
Proc.Natl.Acad.Sci.USA, 119:e2205664119-e2205664119, 2022

PubMed Abstract: Many enzymes utilize redox-coupled centers for performing catalysis where these centers are used to control and regulate the transfer of electrons required for catalysis, whose untimely delivery can lead to a state incapable of binding the substrate, i.e., a dead-end enzyme. Copper nitrite reductases (CuNiRs), which catalyze the reduction of nitrite to nitric oxide (NO), have proven to be a good model system for studying these complex processes including proton-coupled electron transfer (ET) and their orchestration for substrate binding/utilization. Recently, a two-domain CuNiR from a species (NiR) has been discovered with a substantially lower enzymatic activity where the catalytic type-2 Cu (T2Cu) site is occupied by two water molecules requiring their displacement for the substrate nitrite to bind. Single crystal spectroscopy combined with MSOX (multiple structures from one crystal) for both the as-isolated and nitrite-soaked crystals clearly demonstrate that inter-Cu ET within the coupled T1Cu-T2Cu redox system is heavily gated. Laser-flash photolysis and optical spectroscopy showed rapid ET from photoexcited NADH to the T1Cu center but little or no inter-Cu ET in the absence of nitrite. Furthermore, incomplete reoxidation of the T1Cu site (∼20% electrons transferred) was observed in the presence of nitrite, consistent with a slow formation of NO species in the serial structures of the MSOX movie obtained from the nitrite-soaked crystal, which is likely to be responsible for the lower activity of this CuNiR. Our approach is of direct relevance for studying redox reactions in a wide range of biological systems including metalloproteins that make up at least 30% of all proteins.

PubMed: 35862453
DOI: 10.1073/pnas.2205664119

実験手法

X-RAY DIFFRACTION (1.35 Å)