1m9p
From Proteopedia
(New page: 200px<br /> <applet load="1m9p" size="450" color="white" frame="true" align="right" spinBox="true" caption="1m9p, resolution 2.10Å" /> '''Crystalline Human C...) |
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==Overview== | ==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. | 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. | ||
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| + | ==Disease== | ||
| + | Known diseases associated with this structure: Erythremias, alpha- OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141800 141800]], Erythremias, beta- OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141900 141900]], Erythrocytosis OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141850 141850]], HPFH, deletion type OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141900 141900]], Heinz body anemia OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141850 141850]], Heinz body anemias, alpha- OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141800 141800]], Heinz body anemias, beta- OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141900 141900]], Hemoglobin H disease OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141850 141850]], Hypochromic microcytic anemia OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141850 141850]], Methemoglobinemias, alpha- OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141800 141800]], Methemoglobinemias, beta- OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141900 141900]], Sickle cell anemia OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141900 141900]], Thalassemia, alpha- OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141850 141850]], Thalassemia-beta, dominant inclusion-body OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141900 141900]], Thalassemias, alpha- OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141800 141800]], Thalassemias, beta- OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141900 141900]] | ||
==About this Structure== | ==About this Structure== | ||
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[[Category: r2 quaternary state of human hemoglobin]] | [[Category: r2 quaternary state of human hemoglobin]] | ||
| - | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 12 18:09:18 2007'' |
Revision as of 16:02, 12 November 2007
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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 HEM and CMO 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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