3ZCH

Ascorbate peroxidase W41A-H42M mutant

3ZCH の概要

• エントリーDOI: 10.2210/pdb3zch/pdb
• 関連するPDBエントリー: 3ZCG 3ZCY
• 分子名称: ASCORBATE PEROXIDASE, PROTOPORPHYRIN IX CONTAINING FE, SULFATE ION, ... (6 entities in total)
• 機能のキーワード: oxidoreductase, conformational mobility
• 由来する生物種: GLYCINE MAX (SOYBEAN)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 29564.14

構造登録者

Gumiero, A.,Raven, E.L.,Moody, P.C.E. (登録日: 2012-11-20, 公開日: 2012-12-19, 最終更新日: 2023-12-20)

主引用文献

Guimero, A.,Badyal, S.K.,Leeks, T.,Moody, P.C.E.,Raven, E.L.
Probing the Conformational Mobility of the Active Site of Ascorbate Peroxidase
Dalton Trans, 42:3170-, 2013

PubMed Abstract: We have previously demonstrated (Badyal et al., J. Biol. Chem., 2006, 281, 24512) that removal of the active site tryptophan (Trp41) in ascorbate peroxidase increases the conformational mobility of the distal histidine residue (His42) and that His42 coordinates to the iron in the oxidised W41A enzyme to give a 6-coordinate, low-spin peroxidase. In this work, we probe the conformational flexibility of the active site in more detail. We examine whether other residues (Cys, Tyr, Met) can also ligate to the heme at position 42; we find that introduction of other ligating amino acids created a cavity in the heme pocket, but that formation of 6-coordinate heme is not observed. In addition, we examine the role of Asn-71, which hydrogen bonds to His42 and tethers the distal histidine in the active site pocket; we find that removal of this hydrogen bond increases the proportion of low-spin heme. We suggest that, in addition to its well-known role in facilitating the reaction with peroxide, His42 also plays a role in defining the shape and folding of the active site pocket.

PubMed: 23202589
DOI: 10.1039/C2DT32455E

実験手法

X-RAY DIFFRACTION (2 Å)