1F5O
2.9 ANGSTROM CRYSTAL STRUCTURE OF DEOXYGENATED LAMPREY HEMOGLOBIN V IN THE SPACE GROUP P2(1)2(1)2(1)
Summary for 1F5O
| Entry DOI | 10.2210/pdb1f5o/pdb |
| Related | 1F5P 2lhb 3lhb |
| Descriptor | HEMOGLOBIN V, PROTOPORPHYRIN IX CONTAINING FE (3 entities in total) |
| Functional Keywords | hemoglobin, heme, lamprey, oxygen storage-transport complex, oxygen storage/transport |
| Biological source | Petromyzon marinus (sea lamprey) |
| Total number of polymer chains | 6 |
| Total formula weight | 101437.16 |
| Authors | Heaslet, H.A.,Royer Jr., W.E. (deposition date: 2000-06-15, release date: 2000-08-30, Last modification date: 2024-02-07) |
| Primary citation | 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 Cited by 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: 11340069DOI: 10.1074/jbc.M101391200 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.9 Å) |
Structure validation
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