6QQ2

Crystal structure of nitrite bound Y323F mutant of haem-Cu containing nitrite reductase from Ralstonia pickettii

6QQ2 の概要

• エントリーDOI: 10.2210/pdb6qq2/pdb
• 分子名称: Copper-containing nitrite reductase, COPPER (II) ION, NITRITE ION, ... (5 entities in total)
• 機能のキーワード: haem and cu containing nitrite reductase, inter-copper electron transfer, metal binding protein
• 由来する生物種: Ralstonia pickettii
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 50724.12

構造登録者

Antonyuk, S.V.,Shenoy, R.T.,Hedison, T.M.,Eady, R.R.,Hasnain, S.S.,Scrutton, N.S. (登録日: 2019-02-16, 公開日: 2019-11-06, 最終更新日: 2020-02-26)

主引用文献

Hedison, T.M.,Shenoy, R.T.,Iorgu, A.I.,Heyes, D.J.,Fisher, K.,Wright, G.S.A.,Hay, S.,Eady, R.R.,Antonyuk, S.V.,Hasnain, S.S.,Scrutton, N.S.
Unexpected Roles of a Tether Harboring a Tyrosine Gatekeeper Residue in Modular Nitrite Reductase Catalysis.
Acs Catalysis, 9:6087-6099, 2019

PubMed Abstract: It is generally assumed that tethering enhances rates of electron harvesting and delivery to active sites in multidomain enzymes by proximity and sampling mechanisms. Here, we explore this idea in a tethered 3-domain, trimeric copper-containing nitrite reductase. By reverse engineering, we find that tethering does not enhance the rate of electron delivery from its pendant cytochrome to the catalytic copper-containing core. Using a linker that harbors a gatekeeper tyrosine in a nitrite access channel, the tethered haem domain enables catalysis by other mechanisms. Tethering communicates the redox state of the haem to the distant T2Cu center that helps initiate substrate binding for catalysis. It also tunes copper reduction potentials, suppresses reductive enzyme inactivation, enhances enzyme affinity for substrate, and promotes intercopper electron transfer. Tethering has multiple unanticipated beneficial roles, the combination of which fine-tunes function beyond simplistic mechanisms expected from proximity and restrictive sampling models.

PubMed: 32051772
DOI: 10.1021/acscatal.9b01266

実験手法

X-RAY DIFFRACTION (2.6 Å)