1SPG
CARBONMONOXY HEMOGLOBIN FROM THE TELEOST FISH LEIOSTOMUS XANTHURUS
Summary for 1SPG
| Entry DOI | 10.2210/pdb1spg/pdb |
| Descriptor | HEMOGLOBIN, PROTOPORPHYRIN IX CONTAINING FE, CARBON MONOXIDE, ... (5 entities in total) |
| Functional Keywords | carbon monoxide, r-state, leiostomus xanthurus, teleost fish, root effect, globin, oxygen transport |
| Biological source | Leiostomus xanthurus (spot croaker) More |
| Total number of polymer chains | 2 |
| Total formula weight | 33289.99 |
| Authors | Mylvaganam, S.E.,Getzoff, E.D. (deposition date: 1996-02-05, release date: 1997-03-12, Last modification date: 2024-10-16) |
| Primary citation | Mylvaganam, S.E.,Bonaventura, C.,Bonaventura, J.,Getzoff, E.D. Structural basis for the root effect in haemoglobin. Nat.Struct.Biol., 3:275-283, 1996 Cited by PubMed Abstract: The remarkable ability of root effect haemoglobins to pump oxygen against high O2 gradients results from extreme, acid-induced reductions in O2 affinity and cooperativity. The long-sought mechanism for the root effect, revealed by the 2 angstrom crystal structure of the ligand-bound haemoglobin from Leiostomus xanthurus at pH 7.5, unexpectedly involves modulation of the R-state. Key residues strategically assemble positive-charge clusters across the allosteric beta1 beta2-interface in the R-state. At low pH, protonation of the beta N terminus and His 147(HC3)beta within these clusters is postulated to destabilize the R-state and promote the acid-triggered, allosteric R-->T switch with concomitant O2 release. Surprisingly, a set of residues specific to root effect haemoglobins recruit additional residues, conserved among most haemoglobins, to produce the root effect. PubMed: 8605630DOI: 10.1038/nsb0396-275 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.95 Å) |
Structure validation
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