1xjh
From Proteopedia
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|PDB= 1xjh |SIZE=350|CAPTION= <scene name='initialview01'>1xjh</scene> | |PDB= 1xjh |SIZE=350|CAPTION= <scene name='initialview01'>1xjh</scene> | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand=ZN:ZINC ION'>ZN</scene> | + | |LIGAND= <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene> |
|ACTIVITY= | |ACTIVITY= | ||
|GENE= hslO ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]) | |GENE= hslO ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]) | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[1hw7|1HW7]], [[1i7f|1I7F]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1xjh FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1xjh OCA], [http://www.ebi.ac.uk/pdbsum/1xjh PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1xjh RCSB]</span> | ||
}} | }} | ||
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[[Category: Martinez-Yamout, M A.]] | [[Category: Martinez-Yamout, M A.]] | ||
[[Category: Won, H S.]] | [[Category: Won, H S.]] | ||
| - | [[Category: ZN]] | ||
[[Category: four cysteins coordinating zinc]] | [[Category: four cysteins coordinating zinc]] | ||
[[Category: redox-switch domain]] | [[Category: redox-switch domain]] | ||
[[Category: zinc-binding domain]] | [[Category: zinc-binding domain]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 00:50:28 2008'' |
Revision as of 21:50, 30 March 2008
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| Ligands: | |||||||
| Gene: | hslO (Escherichia coli) | ||||||
| Related: | 1HW7, 1I7F
| ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
NMR structure of the redox switch domain of the E. coli Hsp33
Overview
The Escherichia coli chaperone Hsp33 contains a C-terminal zinc-binding domain that modulates activity by a so-called "redox switch". The oxidized form in the absence of zinc is active, while the reduced form in the presence of zinc is inactive. X-ray crystal structures of Hsp33 invariably omit details of the C-terminal domain, which is truncated in protein constructs that are capable of forming crystals. We report the solution structure of a recombinant 61-residue protein containing the zinc-binding domain (residues 227-287) of Hsp33, in the presence of stoichiometric amounts of Zn2+. The zinc-bound protein is well folded, and forms a novel structure unlike other published zinc-binding domains. The structure consists of two helices at right-angles to each other, a two-stranded B-hairpin and a third helix at the C terminus. The zinc site comprises the side-chains of the conserved cysteine residues 232, 234, 262 and 265, and connects a short sequence before the first helix with the tight turn in the middle of the B-hairpin. The structure of the C-terminal zinc-binding domain suggests a mechanism for the operation of the redox switch: loss of the bound zinc ion disrupts the folded structure, allowing the ligand cysteine residues to be oxidized, probably to disulfide bonds. The observation that the C-terminal domain is poorly structured in the active oxidized form suggests that the loss of zinc and unfolding of the domain precedes the oxidation of the thiolate groups of the cysteine residues, since the formation of disulfides between distant parts of the domain sequence would presumably promote the formation of stable three-dimensional structure in the oxidized form.Hsp33 provides an example of a redox signaling system that utilizes protein folding and unfolding together with chemical modification for transduction of external stimuli, in this case oxidative stress, to activate the machinery of the cell that is designed to deal with that stress.
About this Structure
1XJH is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
The zinc-dependent redox switch domain of the chaperone Hsp33 has a novel fold., Won HS, Low LY, Guzman RD, Martinez-Yamout M, Jakob U, Dyson HJ, J Mol Biol. 2004 Aug 20;341(4):893-9. PMID:15328602
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