3sdh
From Proteopedia
(New page: 200px<br /> <applet load="3sdh" size="450" color="white" frame="true" align="right" spinBox="true" caption="3sdh, resolution 1.4Å" /> '''HIGH RESOLUTION CRYS...) |
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caption="3sdh, resolution 1.4Å" /> | caption="3sdh, resolution 1.4Å" /> | ||
'''HIGH RESOLUTION CRYSTALLOGRAPHIC ANALYSIS OF A COOPERATIVE DIMERIC HEMOGLOBIN'''<br /> | '''HIGH RESOLUTION CRYSTALLOGRAPHIC ANALYSIS OF A COOPERATIVE DIMERIC HEMOGLOBIN'''<br /> | ||
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==About this Structure== | ==About this Structure== | ||
| - | 3SDH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Scapharca_inaequivalvis Scapharca inaequivalvis] with HEM and CMO as [http://en.wikipedia.org/wiki/ligands ligands]. This structure superseeds the now removed PDB entry 1SDH. Full crystallographic information is available from [http:// | + | 3SDH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Scapharca_inaequivalvis Scapharca inaequivalvis] with <scene name='pdbligand=HEM:'>HEM</scene> and <scene name='pdbligand=CMO:'>CMO</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. This structure superseeds the now removed PDB entry 1SDH. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3SDH OCA]. |
==Reference== | ==Reference== | ||
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[[Category: oxygen transport]] | [[Category: oxygen transport]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri Feb 15 17:44:13 2008'' |
Revision as of 15:44, 15 February 2008
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HIGH RESOLUTION CRYSTALLOGRAPHIC ANALYSIS OF A COOPERATIVE DIMERIC HEMOGLOBIN
Overview
High-resolution crystal structures of the co-operative dimeric hemoglobin, from the blood clam Scapharca inaequivalvis have been determined in the, unliganded (deoxy) and carbon monoxide (CO) liganded states. The deoxy, structure has been refined at 1.6 A resolution to an R-factor of 0.158 and, the CO structure has been refined at 1.4 A resolution to an R-factor of, 0.159. These structures reveal details of the structural transitions, involved in co-operative ligand binding that involve only a minor rotation, of subunits but very striking tertiary changes at the interface. A small, number of residues in the F-helix appear to mediate co-operativity in this, simple hemoglobin. The oxygen affinity of each subunit appears to be, largely dictated by the disposition of phenylalanine 97, whose side-chain, packs in the heme pocket in the deoxy state but is extruded towards the, interface in the CO-liganded structure. Direct involvement of the, ligand-binding heme group is a novel feature of the subunit interface and, appears important for intersubunit communication. Ligation alters the, conformation of the heme propionate groups along with two interacting, residues from the symmetry-related subunit. These two residues, lysine 96, and asparagine 100, link the heme of one subunit with the F-helix of the, second subunit in such a way as to influence the ligand affinity of that, subunit. The interface is highly hydrated by well-ordered water molecules, that are likely to be important in the stabilization of the two, structures.
About this Structure
3SDH is a Single protein structure of sequence from Scapharca inaequivalvis with and as ligands. This structure superseeds the now removed PDB entry 1SDH. Full crystallographic information is available from OCA.
Reference
High-resolution crystallographic analysis of a co-operative dimeric hemoglobin., Royer WE Jr, J Mol Biol. 1994 Jan 14;235(2):657-81. PMID:8289287
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