1edk
From Proteopedia
(New page: 200px<br /><applet load="1edk" size="450" color="white" frame="true" align="right" spinBox="true" caption="1edk" /> '''STAPHYLOCOCCAL PROTEIN A E-DOMAIN (-60), NMR...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1edk.gif|left|200px]]<br /><applet load="1edk" size=" | + | [[Image:1edk.gif|left|200px]]<br /><applet load="1edk" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1edk" /> | caption="1edk" /> | ||
'''STAPHYLOCOCCAL PROTEIN A E-DOMAIN (-60), NMR, MINIMIZED AVERAGE STRUCTURE'''<br /> | '''STAPHYLOCOCCAL PROTEIN A E-DOMAIN (-60), NMR, MINIMIZED AVERAGE STRUCTURE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The E-domain of staphylococcal protein A is one of five homologous | + | 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== | ==About this Structure== | ||
| - | 1EDK is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus]. Full crystallographic information is available from [http:// | + | 1EDK is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EDK OCA]. |
==Reference== | ==Reference== | ||
| Line 13: | Line 13: | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Staphylococcus aureus]] | [[Category: Staphylococcus aureus]] | ||
| - | [[Category: Fairbrother, W | + | [[Category: Fairbrother, W J.]] |
| - | [[Category: Skelton, N | + | [[Category: Skelton, N J.]] |
| - | [[Category: Starovasnik, M | + | [[Category: Starovasnik, M A.]] |
[[Category: cell wall]] | [[Category: cell wall]] | ||
[[Category: igg-binding protein]] | [[Category: igg-binding protein]] | ||
| Line 23: | Line 23: | ||
[[Category: transmembrane]] | [[Category: transmembrane]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:26:34 2008'' |
Revision as of 10:26, 21 February 2008
|
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
Page seeded by OCA on Thu Feb 21 12:26:34 2008
