1TKW

The transient complex of poplar plastocyanin with turnip cytochrome f determined with paramagnetic NMR

1TKW の概要

• エントリーDOI: 10.2210/pdb1tkw/pdb
• 関連するPDBエントリー: 1hcz 2pcf 5pcy
• 分子名称: Plastocyanin A, Cytochrome f, COPPER (II) ION, ... (4 entities in total)
• 機能のキーワード: electron transfer, photosynthesis, paramagnetic, rigid body calculations
• 由来する生物種: Populus nigra; 詳細
• 細胞内の位置: Plastid, chloroplast thylakoid membrane; Peripheral membrane protein; Lumenal side: P00299; Plastid, chloroplast thylakoid membrane; Single-pass membrane protein: P36438
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 38723.12

構造登録者

Lange, C.,Cornvik, T.,Diaz-Moreno, I.,Ubbink, M. (登録日: 2004-06-09, 公開日: 2005-05-24, 最終更新日: 2026-08-12)

主引用文献

Lange, C.,Cornvik, T.,Diaz-Moreno, I.,Ubbink, M.
The transient complex of poplar plastocyanin with cytochrome f: effects of ionic strength and pH
Biochim.Biophys.Acta, 1707:179-188, 2005

PubMed Abstract: The orientation of poplar plastocyanin in the complex with turnip cytochrome f has been determined by rigid-body calculations using restraints from paramagnetic NMR measurements. The results show that poplar plastocyanin interacts with cytochrome f with the hydrophobic patch of plastocyanin close to the heme region on cytochrome f and via electrostatic interactions between the charged patches on both proteins. Plastocyanin is tilted relative to the orientation reported for spinach plastocyanin, resulting in a longer distance between iron and copper (13.9 A). With increasing ionic strength, from 0.01 to 0.11 M, all observed chemical-shift changes decrease uniformly, supporting the idea that electrostatic forces contribute to complex formation. There is no indication for a rearrangement of the transient complex in this ionic strength range, contrary to what had been proposed earlier on the basis of kinetic data. By decreasing the pH from pH 7.7 to pH 5.5, the complex is destabilized. This may be attributed to the protonation of the conserved acidic patches or the copper ligand His87 in poplar plastocyanin, which are shown to have similar pK(a) values. The results are interpreted in a two-step model for complex formation.

PubMed: 15863096
DOI: 10.1016/j.bbabio.2004.12.002

実験手法

SOLUTION NMR