3J32

An asymmetric unit map from electron cryo-microscopy of Haliotis diversicolor molluscan hemocyanin isoform 1 (HdH1)

3J32 の概要

• エントリーDOI: 10.2210/pdb3j32/pdb
• EMDBエントリー: 5585 5586
• 分子名称: Hemocyanin isoform 1 (1 entity in total)
• 機能のキーワード: allosteric, oxygen transport
• 由来する生物種: Haliotis diversicolor (Abalone)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 757345.62

構造登録者

Zhang, Q.,Dai, X.,Cong, Y.,Zhang, J.,Chen, D.-H.,Dougherty, M.,Wang, J.,Ludtke, S.,Schmid, M.F.,Chiu, W. (登録日: 2013-02-20, 公開日: 2013-04-17, 最終更新日: 2024-02-21)

主引用文献

Zhang, Q.,Dai, X.,Cong, Y.,Zhang, J.,Chen, D.H.,Dougherty, M.T.,Wang, J.,Ludtke, S.J.,Schmid, M.F.,Chiu, W.
Cryo-EM structure of a molluscan hemocyanin suggests its allosteric mechanism.
Structure, 21:604-613, 2013

PubMed Abstract: Hemocyanins are responsible for transporting O2 in the arthropod and molluscan hemolymph. Haliotis diversicolor molluscan hemocyanin isoform 1 (HdH1) is an 8 MDa oligomer. Each subunit is made up of eight functional units (FUs). Each FU contains two Cu ions, which can reversibly bind an oxygen molecule. Here, we report a 4.5 A° cryo-EM structure of HdH1. The structure clearly shows ten asymmetric units arranged with D5 symmetry. Each asymmetric unit contains two structurally distinct but chemically identical subunits. The map is sufficiently resolved to trace the entire subunit Ca backbone and to visualize densities corresponding to some large side chains, Cu ion pairs, and interaction networks of adjacent subunits. A FU topology path intertwining between the two subunits of the asymmetric unit is unambiguously determined. Our observations suggest a structural mechanism for the stability of the entire hemocyanin didecamer and 20 ‘‘communication clusters’’ across asymmetric units responsible for its allosteric property upon oxygen binding.

PubMed: 23541894
DOI: 10.1016/j.str.2013.02.018

実験手法

ELECTRON MICROSCOPY (4.5 Å)