1xx8
From Proteopedia
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| - | [[Image:1xx8.gif|left|200px]] | + | [[Image:1xx8.gif|left|200px]] |
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| - | '''NMR Structure of the W24A Mutant of the Hyperthermophile Sac7d Protein''' | + | {{Structure |
| + | |PDB= 1xx8 |SIZE=350|CAPTION= <scene name='initialview01'>1xx8</scene> | ||
| + | |SITE= | ||
| + | |LIGAND= | ||
| + | |ACTIVITY= | ||
| + | |GENE= sac7d ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=2285 Sulfolobus acidocaldarius]) | ||
| + | }} | ||
| + | |||
| + | '''NMR Structure of the W24A Mutant of the Hyperthermophile Sac7d Protein''' | ||
| + | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1XX8 is a [ | + | 1XX8 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Sulfolobus_acidocaldarius Sulfolobus acidocaldarius]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XX8 OCA]. |
==Reference== | ==Reference== | ||
| - | Role of a surface tryptophan in defining the structure, stability, and DNA binding of the hyperthermophile protein Sac7d., Bedell JL, Edmondson SP, Shriver JW, Biochemistry. 2005 Jan 25;44(3):915-25. PMID:[http:// | + | Role of a surface tryptophan in defining the structure, stability, and DNA binding of the hyperthermophile protein Sac7d., Bedell JL, Edmondson SP, Shriver JW, Biochemistry. 2005 Jan 25;44(3):915-25. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/15654747 15654747] |
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Sulfolobus acidocaldarius]] | [[Category: Sulfolobus acidocaldarius]] | ||
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[[Category: hyperthermophile]] | [[Category: hyperthermophile]] | ||
| - | ''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 15:15:41 2008'' |
Revision as of 13:15, 20 March 2008
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| Gene: | sac7d (Sulfolobus acidocaldarius) | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
NMR Structure of the W24A Mutant of the Hyperthermophile Sac7d Protein
Overview
Sac7d is a small, chromatin protein from Sulfolobus acidocaldarius which induces a sharp kink in DNA with intercalation of valine and methionine side chains. The crystal structure of the protein-DNA complex indicates that a surface tryptophan (W24) plays a key role in DNA binding by hydrogen bonding to the DNA at the kink site. We show here that substitution of the solvent-exposed tryptophan with alanine (W24A) led to a significant loss in not only DNA binding affinity but also protein stability. The W24A substitution proved to be one of the most destabilizing surface substitutions in Sac7d. A global linkage analysis of the pH and salt dependence of stability indicated that the protein stability surface (DeltaG vs temperature, pH, and salt concentration) was lowered overall by 2 kcal/mol (from 0 to 100 degrees C, pH 0 to 7, and 0 to 0.3 M KCl). The lower free energy of unfolding could not be attributed to significant structural perturbations of surface electrostatic interactions. Residual dipolar coupling of partially aligned protein and the NMR solution structure of W24A confirmed that the surface substitution resulted in no significant change in structure. Stabilization of this hyperthermophile protein and its DNA complex by a surface cluster of hydrophobic residues involving W24 and the two intercalating side chains is discussed.
About this Structure
1XX8 is a Single protein structure of sequence from Sulfolobus acidocaldarius. Full crystallographic information is available from OCA.
Reference
Role of a surface tryptophan in defining the structure, stability, and DNA binding of the hyperthermophile protein Sac7d., Bedell JL, Edmondson SP, Shriver JW, Biochemistry. 2005 Jan 25;44(3):915-25. PMID:15654747
Page seeded by OCA on Thu Mar 20 15:15:41 2008
