1F5O

2.9 ANGSTROM CRYSTAL STRUCTURE OF DEOXYGENATED LAMPREY HEMOGLOBIN V IN THE SPACE GROUP P2(1)2(1)2(1)

1F5O の概要

• エントリーDOI: 10.2210/pdb1f5o/pdb
• 関連するPDBエントリー: 1F5P 2lhb 3lhb
• 分子名称: HEMOGLOBIN V, PROTOPORPHYRIN IX CONTAINING FE (3 entities in total)
• 機能のキーワード: hemoglobin, heme, lamprey, oxygen storage-transport complex, oxygen storage/transport
• 由来する生物種: Petromyzon marinus (sea lamprey)
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 101437.16

構造登録者

Heaslet, H.A.,Royer Jr., W.E. (登録日: 2000-06-15, 公開日: 2000-08-30, 最終更新日: 2024-02-07)

主引用文献

Heaslet, H.A.,Royer Jr., W.E.
Crystalline ligand transitions in lamprey hemoglobin. Structural evidence for the regulation of oxygen affinity.
J.Biol.Chem., 276:26230-26236, 2001

PubMed Abstract: The hemoglobins of the Sea Lamprey (Petromyzon marinus) exist in an equilibrium between low affinity oligomers, stabilized by proton binding, and higher affinity monomers, stabilized by oxygen binding. Recent crystallographic analysis revealed that dimerization is coupled with key changes at the ligand binding site with the distal histidine sterically restricting ligand binding in the deoxy dimer but with no significant structural rearrangements on the proximal side. These structural insights led to the hypothesis that oxygen affinity of lamprey hemoglobin is distally regulated. Here we present the 2.9-A crystal structure of deoxygenated lamprey hemoglobin in an orthorhombic crystal form along with the structure of these crystals exposed to carbon monoxide. The hexameric assemblage in this crystal form is very similar to those observed in the previous deoxy structure. Whereas the hydrogen bonding network and packing contacts formed in the dimeric interface of lamprey hemoglobin are largely unaffected by ligand binding, the binding of carbon monoxide induces the distal histidine to swing to positions that would preclude the formation of a stabilizing hydrogen bond with the bound ligand. These results suggest a dual role for the distal histidine and strongly support the hypothesis that ligand affinity in lamprey hemoglobin is distally regulated.

PubMed: 11340069
DOI: 10.1074/jbc.M101391200

実験手法

X-RAY DIFFRACTION (2.9 Å)