8K9P

Neutron X-ray joint structure of pseudoazurin from Alcaligenes faecalis

8K9P の概要

• エントリーDOI: 10.2210/pdb8k9p/pdb
• 関連するPDBエントリー: 8K9N
• 分子名称: Pseudoazurin, COPPER (II) ION, SULFATE ION, ... (4 entities in total)
• 機能のキーワード: blue copper, electron transfer, electron transport
• 由来する生物種: Alcaligenes faecalis
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 13832.47

構造登録者

Fukuda, Y.,Kurihara, K.,Inoue, T.,Tamada, T. (登録日: 2023-08-01, 公開日: 2024-02-14, 最終更新日: 2024-02-21)

主引用文献

Fukuda, Y.,Lintuluoto, M.,Kurihara, K.,Hasegawa, K.,Inoue, T.,Tamada, T.
Overlooked Hydrogen Bond in a Blue Copper Protein Uncovered by Neutron and Sub- angstrom ngstrom Resolution X-ray Crystallography.
Biochemistry, 63:339-347, 2024

PubMed Abstract: Metalloproteins play fundamental roles in organisms and are utilized as starting points for the directed evolution of artificial enzymes. Knowing the strategies of metalloproteins, by which they exquisitely tune their activities, will not only lead to an understanding of biochemical phenomena but also contribute to various applications. The blue copper protein (BCP) has been a renowned model system to understand the biology, chemistry, and physics of metalloproteins. Pseudoazurin (Paz), a blue copper protein, mediates electron transfer in the bacterial anaerobic respiratory chain. Its redox potential is finely tuned by hydrogen (H) bond networks; however, difficulty in visualizing H atom positions in the protein hinders the detailed understanding of the protein's structure-function relationship. We here used neutron and sub-ångström resolution X-ray crystallography to directly observe H atoms in Paz. The 0.86-Å-resolution X-ray structure shows that the peptide bond between Pro80 and the His81 Cu ligand deviates from the ideal planar structure. The 1.9-Å-resolution neutron structure confirms a long-overlooked H bond formed by the amide of His81 and the S atom of another Cu ligand Cys78. Quantum mechanics/molecular mechanics calculations show that this H bond increases the redox potential of the Cu site and explains the experimental results well. Our study demonstrates the potential of neutron and sub-ångström resolution X-ray crystallography to understand the chemistry of metalloproteins at atomic and quantum levels.

PubMed: 38232298
DOI: 10.1021/acs.biochem.3c00517

実験手法

NEUTRON DIFFRACTION (1.9 Å)
X-RAY DIFFRACTION (1.5 Å)