2pq3: Difference between revisions
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[[Image:2pq3.gif|left|200px]] | [[Image:2pq3.gif|left|200px]] | ||
'''N-Terminal Calmodulin Zn-Trapped Intermediate''' | {{Structure | ||
|PDB= 2pq3 |SIZE=350|CAPTION= <scene name='initialview01'>2pq3</scene>, resolution 1.30Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=CAC:CACODYLATE+ION'>CAC</scene> and <scene name='pdbligand=ZN:ZINC ION'>ZN</scene> | |||
|ACTIVITY= | |||
|GENE= Calm1, Calm, Cam, Cam1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=10116 Rattus norvegicus]) | |||
}} | |||
'''N-Terminal Calmodulin Zn-Trapped Intermediate''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
2PQ3 is a [ | 2PQ3 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2PQ3 OCA]. | ||
==Reference== | ==Reference== | ||
A 1.3-A structure of zinc-bound N-terminal domain of calmodulin elucidates potential early ion-binding step., Warren JT, Guo Q, Tang WJ, J Mol Biol. 2007 Nov 23;374(2):517-27. Epub 2007 Sep 21. PMID:[http:// | A 1.3-A structure of zinc-bound N-terminal domain of calmodulin elucidates potential early ion-binding step., Warren JT, Guo Q, Tang WJ, J Mol Biol. 2007 Nov 23;374(2):517-27. Epub 2007 Sep 21. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/17942116 17942116] | ||
[[Category: Rattus norvegicus]] | [[Category: Rattus norvegicus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: n-terminal calmodulin]] | [[Category: n-terminal calmodulin]] | ||
''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 18:16:04 2008'' | ||
Revision as of 19:16, 20 March 2008
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| , resolution 1.30Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | and | ||||||
| Gene: | Calm1, Calm, Cam, Cam1 (Rattus norvegicus) | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
N-Terminal Calmodulin Zn-Trapped Intermediate
OverviewOverview
Calmodulin (CaM) is a 16.8-kDa calcium-binding protein involved in calcium-signal transduction. It is the canonical member of the EF-hand family of proteins, which are characterized by a helix-loop-helix calcium-binding motif. CaM is composed of N- and C-terminal globular domains (N-CaM and C-CaM), and within each domain there are two EF-hand motifs. Upon binding calcium, CaM undergoes a significant, global conformational change involving reorientation of the four helix bundles in each of its two domains. This conformational change upon ion binding is a key component of the signal transduction and regulatory roles of CaM, yet the precise nature of this transition is still unclear. Here, we present a 1.3-A structure of zinc-bound N-terminal calmodulin (N-CaM) solved by single-wavelength anomalous diffraction phasing of a selenomethionyl N-CaM. Our zinc-bound N-CaM structure differs from previously reported CaM structures and resembles calcium-free apo-calmodulin (apo-CaM), despite the zinc binding to both EF-hand motifs. Structural comparison with calcium-free apo-CaM, calcium-loaded CaM, and a cross-linked calcium-loaded CaM suggests that our zinc-bound N-CaM reveals an intermediate step in the initiation of metal ion binding at the first EF-hand motif. Our data also suggest that metal ion coordination by two key residues in the first metal-binding site represents an initial step in the conformational transition induced by metal binding. This is followed by reordering of the N-terminal region of the helix exiting from this first binding loop. This conformational switch should be incorporated into models of either stepwise conformational transition or flexible, dynamic energetic state sampling-based transition.
About this StructureAbout this Structure
2PQ3 is a Single protein structure of sequence from Rattus norvegicus. Full crystallographic information is available from OCA.
ReferenceReference
A 1.3-A structure of zinc-bound N-terminal domain of calmodulin elucidates potential early ion-binding step., Warren JT, Guo Q, Tang WJ, J Mol Biol. 2007 Nov 23;374(2):517-27. Epub 2007 Sep 21. PMID:17942116
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