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4sdh
From Proteopedia
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|PDB= 4sdh |SIZE=350|CAPTION= <scene name='initialview01'>4sdh</scene>, resolution 1.6Å | |PDB= 4sdh |SIZE=350|CAPTION= <scene name='initialview01'>4sdh</scene>, resolution 1.6Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand=HEM:PROTOPORPHYRIN IX CONTAINING FE'>HEM</scene> | + | |LIGAND= <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene> |
|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY= | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4sdh FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4sdh OCA], [http://www.ebi.ac.uk/pdbsum/4sdh PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=4sdh RCSB]</span> | ||
}} | }} | ||
| Line 23: | Line 26: | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Royerjunior, W E.]] | [[Category: Royerjunior, W E.]] | ||
| - | [[Category: HEM]] | ||
[[Category: oxygen transport]] | [[Category: oxygen transport]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 05:40:08 2008'' |
Revision as of 02:40, 31 March 2008
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| , resolution 1.6Å | |||||||
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| Ligands: | |||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
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
4SDH is a Single protein structure of sequence from Scapharca inaequivalvis. This structure supersedes the now removed PDB entry 2SDH. 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
Page seeded by OCA on Mon Mar 31 05:40:08 2008
