3A5B

Crystal structure of a hemoglobin component V from Propsilocerus akamusi (pH6.5 coordinates)

3A5B の概要

• エントリーDOI: 10.2210/pdb3a5b/pdb
• 関連するPDBエントリー: 2ZWJ 3A5A 3A5G 3A5H
• 分子名称: Hemoglobin V, PROTOPORPHYRIN IX CONTAINING FE (3 entities in total)
• 機能のキーワード: hemoglobin, insect, diptera, propsilocerus akamusi, midge larva, heme, oxygen transport, transport
• 由来する生物種: Tokunagayusurika akamusi
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 17835.83

構造登録者

Kuwada, T.,Hasegawa, T.,Takagi, T.,Shishikura, F. (登録日: 2009-08-05, 公開日: 2010-02-09, 最終更新日: 2024-10-23)

主引用文献

Kuwada, T.,Hasegawa, T.,Takagi, T.,Sato, I.,Shishikura, F.
pH-dependent structural changes in haemoglobin component V from the midge larva Propsilocerus akamusi (Orthocladiinae, Diptera)
Acta Crystallogr.,Sect.D, 66:258-267, 2010

PubMed Abstract: Haemoglobin component V (Hb V) from the midge larva Propsilocerus akamusi exhibits oxygen affinity despite the replacement of HisE7 and a pH-dependence of its functional properties. In order to understand the contribution of the distal residue to the ligand-binding properties and the pH-dependent structural changes in this insect Hb, the crystal structure of Hb V was determined under five different pH conditions. Structural comparisons of these Hb structures indicated that at neutral pH ArgE10 contributes to the stabilization of the haem-bound ligand molecule as a functional substitute for the nonpolar E7 residue. However, ArgE10 does not contribute to stabilization at acidic and alkaline pH because of the swinging movement of the Arg side chain under these conditions. This pH-dependent behaviour of Arg results in significant differences in the hydrogen-bond network on the distal side of the haem in the Hb V structures at different pH values. Furthermore, the change in pH results in a partial movement of the F helix, considering that coupled movements of ArgE10 and the F helix determine the haem location at each pH. These results suggested that Hb V retains its functional properties by adapting to the structural changes caused by amino-acid replacements.

PubMed: 20179337
DOI: 10.1107/S0907444909055760

実験手法

X-RAY DIFFRACTION (1.81 Å)