1edk
From Proteopedia
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|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[1edl|1EDL]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1edk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1edk OCA], [http://www.ebi.ac.uk/pdbsum/1edk PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1edk RCSB]</span> | ||
}} | }} | ||
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[[Category: transmembrane]] | [[Category: transmembrane]] | ||
| - | ''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 20:00:27 2008'' |
Revision as of 17:00, 30 March 2008
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| Related: | 1EDL
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
STAPHYLOCOCCAL PROTEIN A E-DOMAIN (-60), NMR, MINIMIZED AVERAGE STRUCTURE
Overview
The E-domain of staphylococcal protein A is one of five homologous IgG-binding domains designated E, D, A, B, and C that comprise the extracellular portion of protein A. The E-domain binds tightly to Fc fragments of IgG and binds certain Fv fragments with micromolar affinity. To explore further the structural features of Fc binding by protein A, and as a first step in developing a structural understanding of E-domain/Fv complex formation, we have determined the solution structure of the uncomplexed E-domain using 2D homonuclear and heteronuclear NMR spectroscopy. Complete 1H and 15N resonance assignments were obtained, and the structure was determined from 383 NOE-derived distance restrains, 34 phi and 19 chi 1 dihedral angle restraints, and 54 restraints for 27 H-bonds. 3JH alpha-H beta coupling constants and long-range NOEs involving Phe11 indicate the side chain exists in more than one conformation with differing chi 1 values. NOE restraints that were incompatible with chi 1 = -60 degrees were removed from one set of structure calculations, and those incompatible with chi 1 = 180 degrees were removed from a second set to allow Phe11 to explore both rotamer wells. Thus, two sets of 20 final structures, having no distance or dihedral angle restraint violations greater than 0.12 A or 1.6 degrees, respectively, represent the solution structure of the E-domain. Backbone atomic rms differences with respect to the mean coordinates for each set of 20 structures for residues 8-53 averaged 0.41 +/- 0.06 and 0.35 +/- 0.06 A. No significant differences in the overall structure result from the different orientations of Phe11. The solution structure of the E-domain consists of three alpha-helices that pack together to form a compact helical bundle. A detailed comparison between the E-domain ensembles and the previously determined structure for the B-domain in complex with Fc indicates that only the 180 degrees chi 1 rotamer of Phe11 is competent for binding; the -60 degrees chi 1 rotamer must reorient to 180 degrees to create a cavity that is filled by Ile253 from the CH2 domain of Fc in the Fc-bound complex.
About this Structure
1EDK is a Single protein structure of sequence from Staphylococcus aureus. Full crystallographic information is available from OCA.
Reference
Solution structure of the E-domain of staphylococcal protein A., Starovasnik MA, Skelton NJ, O'Connell MP, Kelley RF, Reilly D, Fairbrother WJ, Biochemistry. 1996 Dec 3;35(48):15558-69. PMID:8952510
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