2C0K

The structure of hemoglobin from the botfly Gasterophilus intestinalis

2C0K の概要

• エントリーDOI: 10.2210/pdb2c0k/pdb
• 分子名称: HEMOGLOBIN, PROTOPORPHYRIN IX CONTAINING FE, OXYGEN MOLECULE, ... (4 entities in total)
• 機能のキーワード: oxygen transport, gasterophilus intestinalis hemoglobin, insect hemoglobin, heme, iron, metal-binding
• 由来する生物種: GASTEROPHILUS INTESTINALIS
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 37212.29

構造登録者

Pesce, A.,Nardini, M.,Dewilde, S.,Hoogewijs, D.,Ascenzi, P.,Moens, L.,Bolognesi, M. (登録日: 2005-09-05, 公開日: 2005-11-09, 最終更新日: 2023-12-13)

主引用文献

Pesce, A.,Nardini, M.,Dewilde, S.,Hoogewijs, D.,Ascenzi, P.,Moens, L.,Bolognesi, M.
Modulation of Oxygen Binding to Insect Hemoglobins: The Structure of Hemoglobin from the Botfly Gasterophilus Intestinalis.
Protein Sci., 14:3057-, 2005

PubMed Abstract: Hemoglobins (Hbs) reversibly bind gaseous diatomic ligands (e.g., O2) as the sixth heme axial ligand of the penta-coordinate deoxygenated form. Selected members of the Hb superfamily, however, display a functionally relevant hexa-coordinate heme Fe atom in their deoxygenated state. Endogenous heme hexa-coordination is generally provided in these Hbs by the E7 residue (often His), which thus modulates accessibility to the heme distal pocket and reactivity of the heme toward exogenous ligands. Such a pivotal role of the E7 residue is prominently shown by analysis of the functional and structural properties of insect Hbs. Here, we report the 2.6 A crystal structure of oxygenated Gasterophilus intestinalis Hb1, a Hb known to display a penta-coordinate heme in the deoxygenated form. The structure is analyzed in comparison with those of Drosophila melanogaster Hb, exhibiting a hexa-coordinate heme in its deoxygenated derivative, and of Chironomus thummi thummi HbIII, which displays a penta-coordinate heme in the deoxygenated form. Despite evident structural differences in the heme distal pockets, the distinct molecular mechanisms regulating O2 binding to the three insect Hbs result in similar O(2 affinities (P50 values ranging between 0.12 torr and 0.46 torr).

PubMed: 16260762
DOI: 10.1110/PS.051742605

実験手法

X-RAY DIFFRACTION (2.6 Å)