1xrz
From Proteopedia
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| - | [[Image:1xrz.jpg|left|200px]] | + | [[Image:1xrz.jpg|left|200px]] |
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| - | '''NMR Structure of a Zinc Finger with Cyclohexanylalanine Substituted for the Central Aromatic Residue''' | + | {{Structure |
| + | |PDB= 1xrz |SIZE=350|CAPTION= <scene name='initialview01'>1xrz</scene> | ||
| + | |SITE= | ||
| + | |LIGAND= <scene name='pdbligand=ZN:ZINC ION'>ZN</scene> | ||
| + | |ACTIVITY= | ||
| + | |GENE= | ||
| + | }} | ||
| + | |||
| + | '''NMR Structure of a Zinc Finger with Cyclohexanylalanine Substituted for the Central Aromatic Residue''' | ||
| + | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1XRZ is a [ | + | 1XRZ is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XRZ OCA]. |
==Reference== | ==Reference== | ||
| - | Solvation and the hidden thermodynamics of a zinc finger probed by nonstandard repair of a protein crevice., Lachenmann MJ, Ladbury JE, Qian X, Huang K, Singh R, Weiss MA, Protein Sci. 2004 Dec;13(12):3115-26. PMID:[http:// | + | Solvation and the hidden thermodynamics of a zinc finger probed by nonstandard repair of a protein crevice., Lachenmann MJ, Ladbury JE, Qian X, Huang K, Singh R, Weiss MA, Protein Sci. 2004 Dec;13(12):3115-26. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/15557258 15557258] |
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Huang, K.]] | [[Category: Huang, K.]] | ||
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[[Category: zinc finger]] | [[Category: zinc finger]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 15:13:49 2008'' |
Revision as of 13:13, 20 March 2008
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| Coordinates: | save as pdb, mmCIF, xml | ||||||
NMR Structure of a Zinc Finger with Cyclohexanylalanine Substituted for the Central Aromatic Residue
Contents |
Overview
The classical Zn finger contains a phenylalanine at the crux of its three architectural elements: a beta-hairpin, an alpha-helix, and a Zn(2+)-binding site. Surprisingly, phenylalanine is not required for high-affinity Zn2+ binding, but instead contributes to the specification of a precise DNA-binding surface. Substitution of phenylalanine by leucine leads to a floppy but native-like structure whose Zn affinity is maintained by marked entropy-enthalpy compensation (DeltaDeltaH -8.3 kcal/mol and -TDeltaDeltaS 7.7 kcal/mol). Phenylalanine and leucine differ in shape, size, and aromaticity. To distinguish which features correlate with dynamic stability, we have investigated a nonstandard finger containing cyclohexanylalanine at this site. The structure of the nonstandard finger is similar to that of the native domain. The cyclohexanyl ring assumes a chair conformation, and conformational fluctuations characteristic of the leucine variant are damped. Although the nonstandard finger exhibits a lower affinity for Zn2+ than does the native domain (DeltaDeltaG -1.2 kcal/mol), leucine-associated perturbations in enthalpy and entropy are almost completely attenuated (DeltaDeltaH -0.7 kcal/mol and -TDeltaDeltaS -0.5 kcal/mol). Strikingly, global changes in entropy (as inferred from calorimetry) are in each case opposite in sign from changes in configurational entropy (as inferred from NMR). This seeming paradox suggests that enthalpy-entropy compensation is dominated by solvent reorganization rather than nominal molecular properties. Together, these results demonstrate that dynamic and thermodynamic perturbations correlate with formation or repair of a solvated packing defect rather than type of physical interaction (aromatic or aliphatic) within the core.
Disease
Known disease associated with this structure: Spastic paraplegia 33 OMIM:[610243]
About this Structure
1XRZ is a Single protein structure of sequence from [1]. Full crystallographic information is available from OCA.
Reference
Solvation and the hidden thermodynamics of a zinc finger probed by nonstandard repair of a protein crevice., Lachenmann MJ, Ladbury JE, Qian X, Huang K, Singh R, Weiss MA, Protein Sci. 2004 Dec;13(12):3115-26. PMID:15557258
Page seeded by OCA on Thu Mar 20 15:13:49 2008
