1ezl
From Proteopedia
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|PDB= 1ezl |SIZE=350|CAPTION= <scene name='initialview01'>1ezl</scene>, resolution 2.0Å | |PDB= 1ezl |SIZE=350|CAPTION= <scene name='initialview01'>1ezl</scene>, resolution 2.0Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand=CU:COPPER (II) ION'>CU</scene> | + | |LIGAND= <scene name='pdbligand=CU:COPPER+(II)+ION'>CU</scene> |
|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY= | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1ezl FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ezl OCA], [http://www.ebi.ac.uk/pdbsum/1ezl PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1ezl RCSB]</span> | ||
}} | }} | ||
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[[Category: Leckner, J.]] | [[Category: Leckner, J.]] | ||
[[Category: Sjolin, L.]] | [[Category: Sjolin, L.]] | ||
| - | [[Category: CU]] | ||
[[Category: crystal structure]] | [[Category: crystal structure]] | ||
[[Category: disulphide bond]] | [[Category: disulphide bond]] | ||
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[[Category: protein folding]] | [[Category: protein folding]] | ||
| - | ''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 20:12:50 2008'' |
Revision as of 17:12, 30 March 2008
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| , resolution 2.0Å | |||||||
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| Ligands: | |||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
CRYSTAL STRUCTURE OF THE DISULPHIDE BOND-DEFICIENT AZURIN MUTANT C3A/C26A: HOW IMPORTANT IS THE S-S BOND FOR FOLDING AND STABILITY?
Overview
Azurin has a beta-barrel fold comprising eight beta-strands and one alpha helix. A disulfide bond between residues 3 and 26 connects the N-termini of beta strands beta1 and beta3. Three mutant proteins lacking the disulfide bond were constructed, C3A/C26A, C3A/C26I and a putative salt bridge (SB) in the C3A/S25R/C26A/K27R mutant. All three mutants exhibit spectroscopic properties similar to the wild-type protein. Furthermore, the crystal structure of the C3A/C26A mutant was determined at 2.0 A resolution and, in comparison to the wild-type protein, the only differences are found in the immediate proximity of the mutation. The mutants lose the 628 nm charge-transfer band at a temperature 10-22 degrees C lower than the wild-type protein. The folding of the zinc loaded C3A/C26A mutant was studied by guanidine hydrochloride (GdnHCl) induced denaturation monitored both by fluorescence and CD spectroscopy. The midpoint in the folding equilibrium, at 1.3 M GdnHCl, was observed using both CD and fluorescence spectroscopy. The free energy of folding determined from CD is -24.9 kJ.mol-1, a destabilization of approximately 20 kJ.mol-1 compared to the wild-type Zn2+-protein carrying an intact disulfide bond, indicating that the disulfide bond is important for giving azurin its stable structure. The C3A/C26I mutant is more stable and the SB mutant is less stable than C3A/C26A, both in terms of folding energy and thermal denaturation. The folding intermediate of the wild-type Zn2+-azurin is not observed for the disulfide-deficient C3A/C26A mutant. The rate of unfolding for the C3A/C26A mutant is similar to that of the wild-type protein, suggesting that the site of the mutation is not involved in an early unfolding reaction.
About this Structure
1EZL is a Single protein structure of sequence from Pseudomonas aeruginosa. Full crystallographic information is available from OCA.
Reference
Crystal structure of the disulfide bond-deficient azurin mutant C3A/C26A: how important is the S-S bond for folding and stability?, Bonander N, Leckner J, Guo H, Karlsson BG, Sjolin L, Eur J Biochem. 2000 Jul;267(14):4511-9. PMID:10880975
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