1ash
From Proteopedia
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|PDB= 1ash |SIZE=350|CAPTION= <scene name='initialview01'>1ash</scene>, resolution 2.15Å | |PDB= 1ash |SIZE=350|CAPTION= <scene name='initialview01'>1ash</scene>, resolution 2.15Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene> | + | |LIGAND= <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=OXY:OXYGEN+MOLECULE'>OXY</scene> |
|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY= | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1ash FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ash OCA], [http://www.ebi.ac.uk/pdbsum/1ash PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1ash RCSB]</span> | ||
}} | }} | ||
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[[Category: Mathews, F S.]] | [[Category: Mathews, F S.]] | ||
[[Category: Yang, J.]] | [[Category: Yang, J.]] | ||
| - | [[Category: HEM]] | ||
| - | [[Category: OXY]] | ||
[[Category: oxygen storage]] | [[Category: oxygen storage]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 18:46:45 2008'' |
Revision as of 15:46, 30 March 2008
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| , resolution 2.15Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
THE STRUCTURE OF ASCARIS HEMOGLOBIN DOMAIN I AT 2.2 ANGSTROMS RESOLUTION: MOLECULAR FEATURES OF OXYGEN AVIDITY
Overview
The perienteric hemoglobin of the parasitic nematode Ascaris has an exceptionally high affinity for oxygen. It is an octameric protein containing two similar heme-binding domains per subunit, but recombinant constructs expressing a single, monomeric heme-binding domain (domain 1; D1) retain full oxygen avidity. We have solved the crystal structure of D1 at 2.2 A resolution. Analysis of the structure reveals a characteristic globin fold and illuminates molecular features involved in oxygen avidity of Ascaris perienteric hemoglobin. A strong hydrogen bond between tyrosine at position 10 in the B helix (tyrosine-B10) and the distal oxygen of the ligand, combined with a weak hydrogen bond between glutamine-E7 and the proximal oxygen, grips the ligand in the binding pocket. A third hydrogen bond between these two amino acids appears to stabilize the structure. The B helix of D1 is displaced laterally by 2.5 A when compared with sperm whale myoglobin. This shifts the tyrosine-B10 hydroxyl far enough from liganded oxygen to form a strong hydrogen bond without steric hindrance. Changes in the F helix compared with myoglobin contribute to a tilted heme that may also be important for oxygen affinity.
About this Structure
1ASH is a Single protein structure of sequence from Ascaris suum. Full crystallographic information is available from OCA.
Reference
The structure of Ascaris hemoglobin domain I at 2.2 A resolution: molecular features of oxygen avidity., Yang J, Kloek AP, Goldberg DE, Mathews FS, Proc Natl Acad Sci U S A. 1995 May 9;92(10):4224-8. PMID:7753786
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