1oaj: Difference between revisions
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'''ACTIVE SITE COPPER AND ZINC IONS MODULATE THE QUATERNARY STRUCTURE OF PROKARYOTIC CU,ZN SUPEROXIDE DISMUTASE''' | {{Structure | ||
|PDB= 1oaj |SIZE=350|CAPTION= <scene name='initialview01'>1oaj</scene>, resolution 1.73Å | |||
|SITE= <scene name='pdbsite=AC1:Cu+Binding+Site+For+Chain+A'>AC1</scene> | |||
|LIGAND= <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene> and <scene name='pdbligand=CU:COPPER (II) ION'>CU</scene> | |||
|ACTIVITY= [http://en.wikipedia.org/wiki/Superoxide_dismutase Superoxide dismutase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.15.1.1 1.15.1.1] | |||
|GENE= | |||
}} | |||
'''ACTIVE SITE COPPER AND ZINC IONS MODULATE THE QUATERNARY STRUCTURE OF PROKARYOTIC CU,ZN SUPEROXIDE DISMUTASE''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1OAJ is a [ | 1OAJ is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Photobacterium_leiognathi Photobacterium leiognathi]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1OAJ OCA]. | ||
==Reference== | ==Reference== | ||
Active-site copper and zinc ions modulate the quaternary structure of prokaryotic Cu,Zn superoxide dismutase., Cioni P, Pesce A, Morozzo della Rocca B, Castelli S, Falconi M, Parrilli L, Bolognesi M, Strambini G, Desideri A, J Mol Biol. 2003 Mar 7;326(5):1351-60. PMID:[http:// | Active-site copper and zinc ions modulate the quaternary structure of prokaryotic Cu,Zn superoxide dismutase., Cioni P, Pesce A, Morozzo della Rocca B, Castelli S, Falconi M, Parrilli L, Bolognesi M, Strambini G, Desideri A, J Mol Biol. 2003 Mar 7;326(5):1351-60. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/12595249 12595249] | ||
[[Category: Photobacterium leiognathi]] | [[Category: Photobacterium leiognathi]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: zn superoxide dismutase]] | [[Category: zn superoxide dismutase]] | ||
''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 13:08:10 2008'' | ||
Revision as of 14:08, 20 March 2008
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| , resolution 1.73Å | |||||||
|---|---|---|---|---|---|---|---|
| Sites: | |||||||
| Ligands: | and | ||||||
| Activity: | Superoxide dismutase, with EC number 1.15.1.1 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
ACTIVE SITE COPPER AND ZINC IONS MODULATE THE QUATERNARY STRUCTURE OF PROKARYOTIC CU,ZN SUPEROXIDE DISMUTASE
OverviewOverview
The influence of the constitutive metal ions on the equilibrium properties of dimeric Photobacterium leiognathi Cu,Zn superoxide dismutase has been studied for the wild-type and for two mutant protein forms bearing a negative charge in the amino acid clusters at the dimer association interface. Depletion of copper and zinc dissociates the two mutant proteins into monomers, which reassemble toward the dimeric state upon addition of stoichiometric amounts of zinc. Pressure-dependent dissociation is observed for the copper-depleted wild-type and mutated enzymes, as monitored by the fluorescence shift of a unique tryptophan residue located at the subunit association interface. The spectral shift occurs slowly, reaching a plateau after 15-20 minutes, and is fully reversible. The recovery of the original fluorescence properties, after decompression, is fast (less than four minutes), suggesting that the isolated subunit has a relatively stable structure, and excluding the presence of stable intermediates during the dimer-monomer transition. The dimer dissociation process is still incomplete at 6.5 kbar for the copper-depleted wild-type and mutated enzymes, at variance with what is generally observed for oligomeric proteins that dissociate below 3 kbar. Measurement of the degree of dissociation, at two different protein concentrations, allows us to calculate the standard volume variation upon association, Delta V, and the dissociation constant K(d0), at atmospheric pressure, (25 ml/mol and 3 x 10(-7)M, respectively). The holoprotein is fully dimeric even at 6.5 kbar, which allows us to evaluate a lower Delta G degrees limit of 11.5 kcal/mol, corresponding to a dissociation constant K(d0)<10(-9)M.
About this StructureAbout this Structure
1OAJ is a Single protein structure of sequence from Photobacterium leiognathi. Full crystallographic information is available from OCA.
ReferenceReference
Active-site copper and zinc ions modulate the quaternary structure of prokaryotic Cu,Zn superoxide dismutase., Cioni P, Pesce A, Morozzo della Rocca B, Castelli S, Falconi M, Parrilli L, Bolognesi M, Strambini G, Desideri A, J Mol Biol. 2003 Mar 7;326(5):1351-60. PMID:12595249
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