2BIH

crystal structure of the Molybdenum-containing nitrate reducing fragment of Pichia angusta assimilatory nitrate reductase

2BIH の概要

• エントリーDOI: 10.2210/pdb2bih/pdb
• 関連するPDBエントリー: 2BII
• 分子名称: NITRATE REDUCTASE [NADPH], (MOLYBDOPTERIN-S,S)-DIOXO-THIO-MOLYBDENUM(IV) (3 entities in total)
• 機能のキーワード: flavoprotein, nitrate assimilation, oxidoreductase
• 由来する生物種: PICHIA ANGUSTA
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 54906.13

構造登録者

Fischer, K.,Barbier, G.,Hecht, H.-J.,Mendel, R.R.,Campbell, W.H.,Schwarz, G. (登録日: 2005-01-21, 公開日: 2005-03-30, 最終更新日: 2023-12-13)

主引用文献

Fischer, K.,Barbier, G.,Hecht, H.-J.,Mendel, R.R.,Campbell, W.H.,Schwarz, G.
Structural Basis of Eukaryotic Nitrate Reduction: Crystal Structures of the Nitrate Reductase Active Site
Plant Cell, 17:1167-, 2005

PubMed Abstract: Nitrate assimilation in autotrophs provides most of the reduced nitrogen on earth. In eukaryotes, reduction of nitrate to nitrite is catalyzed by the molybdenum-containing NAD(P)H:nitrate reductase (NR; EC 1.7.1.1-3). In addition to the molybdenum center, NR contains iron-heme and flavin adenine dinucleotide as redox cofactors involved in an internal electron transport chain from NAD(P)H to nitrate. Recombinant, catalytically active Pichia angusta nitrate-reducing, molybdenum-containing fragment (NR-Mo) was expressed in P. pastoris and purified. Crystal structures for NR-Mo were determined at 1.7 and 2.6 angstroms. These structures revealed a unique slot for binding nitrate in the active site and identified key Arg and Trp residues potentially involved in nitrate binding. Dimeric NR-Mo is similar in overall structure to sulfite oxidases, with significant differences in the active site. Sulfate bound in the active site caused conformational changes, as compared with the unbound enzyme. Four ordered water molecules located in close proximity to Mo define a nitrate binding site, a penta-coordinated reaction intermediate, and product release. Because yeast NAD(P)H:NR is representative of the family of eukaryotic NR, we propose a general mechanism for nitrate reduction catalysis.

PubMed: 15772287
DOI: 10.1105/TPC.104.029694

実験手法

X-RAY DIFFRACTION (2.6 Å)