1m9p
From Proteopedia
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- | [[Image:1m9p.gif|left|200px]]<br /> | + | [[Image:1m9p.gif|left|200px]]<br /><applet load="1m9p" size="350" color="white" frame="true" align="right" spinBox="true" |
- | <applet load="1m9p" size=" | + | |
caption="1m9p, resolution 2.10Å" /> | caption="1m9p, resolution 2.10Å" /> | ||
'''Crystalline Human Carbonmonoxy Hemoglobin C Exhibits The R2 Quaternary State at Neutral pH In The Presence of Polyethylene Glycol: The 2.1 Angstrom Resolution Crystal Structure'''<br /> | '''Crystalline Human Carbonmonoxy Hemoglobin C Exhibits The R2 Quaternary State at Neutral pH In The Presence of Polyethylene Glycol: The 2.1 Angstrom Resolution Crystal Structure'''<br /> | ||
==Overview== | ==Overview== | ||
- | Human hemoglobin binds oxygen cooperatively and functions as a tetramer | + | Human hemoglobin binds oxygen cooperatively and functions as a tetramer composed of two identical alphabeta heterodimers. While human hemoglobin is the best characterized allosteric protein, the quaternary R (oxygenated or liganded) to T (deoxygenated) structural transition remains controversial. The R2 state has been postulated to represent either an intermediate or final quaternary state elicited by ligand binding. However, the biological relevance of the R2 state has been questioned as it has not been observed crystallographically under physiological conditions. The high-resolution R2 quaternary structures of human COHbC (betaE6K) and COHbS (betaE6V) are reported at neutral pH and low ionic strength using PEG 4000 as a precipitant. Crystals of COHbC, COHbS and their mixtures are isomorphous, indicating that they share the same tertiary and quaternary structures. In contrast, oxyHbA or COHbA did not yield crystals at neutral pH under similar conditions. Solubility studies and modeling suggest that at neutral pH and low ionic strength the beta6 mutant hemoglobins crystallize (betaK6 > betaV6) as a result of more favorable lattice contacts. |
==Disease== | ==Disease== | ||
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==About this Structure== | ==About this Structure== | ||
- | 1M9P is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with HEM and CMO as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1M9P is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=HEM:'>HEM</scene> and <scene name='pdbligand=CMO:'>CMO</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1M9P OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
- | [[Category: Almo, S | + | [[Category: Almo, S C.]] |
- | [[Category: Hirsch, R | + | [[Category: Hirsch, R E.]] |
- | [[Category: Patskovska, L | + | [[Category: Patskovska, L N.]] |
- | [[Category: Patskovsky, Y | + | [[Category: Patskovsky, Y V.]] |
[[Category: CMO]] | [[Category: CMO]] | ||
[[Category: HEM]] | [[Category: HEM]] | ||
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[[Category: r2 quaternary state of human hemoglobin]] | [[Category: r2 quaternary state of human hemoglobin]] | ||
- | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:52:58 2008'' |
Revision as of 11:53, 21 February 2008
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Crystalline Human Carbonmonoxy Hemoglobin C Exhibits The R2 Quaternary State at Neutral pH In The Presence of Polyethylene Glycol: The 2.1 Angstrom Resolution Crystal Structure
Contents |
Overview
Human hemoglobin binds oxygen cooperatively and functions as a tetramer composed of two identical alphabeta heterodimers. While human hemoglobin is the best characterized allosteric protein, the quaternary R (oxygenated or liganded) to T (deoxygenated) structural transition remains controversial. The R2 state has been postulated to represent either an intermediate or final quaternary state elicited by ligand binding. However, the biological relevance of the R2 state has been questioned as it has not been observed crystallographically under physiological conditions. The high-resolution R2 quaternary structures of human COHbC (betaE6K) and COHbS (betaE6V) are reported at neutral pH and low ionic strength using PEG 4000 as a precipitant. Crystals of COHbC, COHbS and their mixtures are isomorphous, indicating that they share the same tertiary and quaternary structures. In contrast, oxyHbA or COHbA did not yield crystals at neutral pH under similar conditions. Solubility studies and modeling suggest that at neutral pH and low ionic strength the beta6 mutant hemoglobins crystallize (betaK6 > betaV6) as a result of more favorable lattice contacts.
Disease
Known diseases associated with this structure: Erythremias, alpha- OMIM:[141800], Erythremias, beta- OMIM:[141900], Erythrocytosis OMIM:[141850], HPFH, deletion type OMIM:[141900], Heinz body anemia OMIM:[141850], Heinz body anemias, alpha- OMIM:[141800], Heinz body anemias, beta- OMIM:[141900], Hemoglobin H disease OMIM:[141850], Hypochromic microcytic anemia OMIM:[141850], Methemoglobinemias, alpha- OMIM:[141800], Methemoglobinemias, beta- OMIM:[141900], Sickle cell anemia OMIM:[141900], Thalassemia, alpha- OMIM:[141850], Thalassemia-beta, dominant inclusion-body OMIM:[141900], Thalassemias, alpha- OMIM:[141800], Thalassemias, beta- OMIM:[141900]
About this Structure
1M9P is a Protein complex structure of sequences from Homo sapiens with and as ligands. Full crystallographic information is available from OCA.
Reference
COHbC and COHbS crystallize in the R2 quaternary state at neutral pH in the presence of PEG 4000., Patskovska LN, Patskovsky YV, Almo SC, Hirsch RE, Acta Crystallogr D Biol Crystallogr. 2005 May;61(Pt 5):566-73. Epub 2005, Apr 20. PMID:15858266
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