2pq3: Difference between revisions
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|PDB= 2pq3 |SIZE=350|CAPTION= <scene name='initialview01'>2pq3</scene>, resolution 1.30Å | |PDB= 2pq3 |SIZE=350|CAPTION= <scene name='initialview01'>2pq3</scene>, resolution 1.30Å | ||
|SITE= | |SITE= | ||
|LIGAND= <scene name='pdbligand=CAC:CACODYLATE+ION'>CAC</scene> | |LIGAND= <scene name='pdbligand=CAC:CACODYLATE+ION'>CAC</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene> | ||
|ACTIVITY= | |ACTIVITY= | ||
|GENE= Calm1, Calm, Cam, Cam1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=10116 Rattus norvegicus]) | |GENE= Calm1, Calm, Cam, Cam1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=10116 Rattus norvegicus]) | ||
|DOMAIN= | |||
|RELATEDENTRY= | |||
|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2pq3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2pq3 OCA], [http://www.ebi.ac.uk/pdbsum/2pq3 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=2pq3 RCSB]</span> | |||
}} | }} | ||
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[[Category: Tang, W J.]] | [[Category: Tang, W J.]] | ||
[[Category: Warren, J T.]] | [[Category: Warren, J T.]] | ||
[[Category: calmodulin]] | [[Category: calmodulin]] | ||
[[Category: cam]] | [[Category: cam]] | ||
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[[Category: n-terminal calmodulin]] | [[Category: n-terminal calmodulin]] | ||
''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 04:39:15 2008'' | ||
Revision as of 04:39, 31 March 2008
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| , resolution 1.30Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , | ||||||
| Gene: | Calm1, Calm, Cam, Cam1 (Rattus norvegicus) | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| 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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