Calcium-free Calmodulin: Difference between revisions

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Calmodulin is a molecule that has been studied extensively in its functions within the cell, and has an important role in relaying Ca2+ signals within the cytosol. <ref name="1CRT">Hoeflich, K.P., & Ikura, M.. Calmodulin in action: diversity in target recognition and activation mechanisms, Cell. 2002 108:739-742</ref> It does this by binding to Ca2+, undergoing a conformational change, and may interact with various proteins within the cell.<ref name="1CRT"/><ref name="4CRT">PMID: 7552748</ref><ref name="3CRT">PMID: 3145979</ref> Once bound to a target protein, it undergoes a further conformational change and may activate certain systems. For example, there is a Ca2+ pump in the plasma membrane pump that is activated by the binding of Ca2+-bound calmodulin, and then uses ATP to drive the Ca2+ out of the cell. <ref name="6CRT">PMID: 12838335</ref>  
Calmodulin is a molecule that has been studied extensively in its functions within the cell, and has an important role in relaying Ca2+ signals within the cytosol. <ref name="1CRT">Hoeflich, K.P., & Ikura, M.. Calmodulin in action: diversity in target recognition and activation mechanisms, Cell. 2002 108:739-742</ref> It does this by binding to Ca2+, undergoing a conformational change, and may interact with various proteins within the cell.<ref name="1CRT"/><ref name="4CRT">PMID: 7552748</ref><ref name="3CRT">PMID: 3145979</ref> Once bound to a target protein, it undergoes a further conformational change and may activate certain systems. For example, there is a Ca2+ pump in the plasma membrane pump that is activated by the binding of Ca2+-bound calmodulin, and then uses ATP to drive the Ca2+ out of the cell. <ref name="6CRT">PMID: 12838335</ref>  


==='''Calcium-bound Calmodulin'''===
=='''Calcium-bound Calmodulin'''==


[[Image:3cln.png|left|200px]]
[[Image:3cln.png|left|200px]]
The structure of calcium-bound calmodulin had previously been discovered using x-ray crystallography <ref name="3CRT"/>. It was then theorized that knowledge of the structure of calcium-free calmodulin would give greater insight into the function of the protein. Attempts were made to crystallize the calcium-free (or apo) form, but to no avail, thus it was decided that the only way to get a good idea of the structure would be to use several NMR experiments.
The structure of calcium-bound calmodulin had previously been discovered using x-ray crystallography. <ref name="3CRT"/> It was then theorized that knowledge of the structure of calcium-free calmodulin would give greater insight into the function of the protein. Attempts were made to crystallize the calcium-free (or apo) form, but to no avail, thus it was decided that the only way to get a good idea of the structure would be to use several NMR experiments. <ref name="4CRT"/>


==='''Calcium-bound Calmodulin'''===


[[Image:calmodulin.png|left|200px]]


=='''Calcium-free Calmodulin'''==
[[Image:calmodulin.png|right|200px]]
The structure of calcium-free calmodulin was discovered by doing several different NMR experiments that included ROE, reverse labelling of Phe residues, and 3-bond J-couplings. <ref name="4CRT"/> It was theorized that by comparing the results of the NMR experiments for the apo calmodulin with the calcium-bound calmodulin, information could be gleaned as to the structural changes that occur when calcium is bound. It was discovered that the series of residues




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==References==
==References==
<references/>
<references/>
<ref group="xtra">PMID:3145979</ref><references group="xtra"/>
<ref group="xtra">PMID:7552748</ref><references group="xtra"/>

Revision as of 06:29, 1 April 2010

Please do NOT make changes to this Sandbox until after April 23, 2010. Sandboxes 151-200 are reserved until then for use by the Chemistry 307 class at UNBC taught by Prof. [[User:Andrea Gorrell|Andrea Chris Truscott

Calcium-free Calmodulin

Drag the structure with the mouse to rotate
1cfc, 25 NMR models (default scene)
Related: 1cfd
Resources: FirstGlance, OCA, RCSB, PDBsum
Coordinates: save as pdb, mmCIF, xml



General Information


Calmodulin is a molecule that has been studied extensively in its functions within the cell, and has an important role in relaying Ca2+ signals within the cytosol. [1] It does this by binding to Ca2+, undergoing a conformational change, and may interact with various proteins within the cell.[1][2][3] Once bound to a target protein, it undergoes a further conformational change and may activate certain systems. For example, there is a Ca2+ pump in the plasma membrane pump that is activated by the binding of Ca2+-bound calmodulin, and then uses ATP to drive the Ca2+ out of the cell. [4]

Calcium-bound Calmodulin

The structure of calcium-bound calmodulin had previously been discovered using x-ray crystallography. [3] It was then theorized that knowledge of the structure of calcium-free calmodulin would give greater insight into the function of the protein. Attempts were made to crystallize the calcium-free (or apo) form, but to no avail, thus it was decided that the only way to get a good idea of the structure would be to use several NMR experiments. [2]





Calcium-free Calmodulin

The structure of calcium-free calmodulin was discovered by doing several different NMR experiments that included ROE, reverse labelling of Phe residues, and 3-bond J-couplings. [2] It was theorized that by comparing the results of the NMR experiments for the apo calmodulin with the calcium-bound calmodulin, information could be gleaned as to the structural changes that occur when calcium is bound. It was discovered that the series of residues





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References

  1. ↑ 1.0 1.1 Hoeflich, K.P., & Ikura, M.. Calmodulin in action: diversity in target recognition and activation mechanisms, Cell. 2002 108:739-742
  2. ↑ 2.0 2.1 2.2 Kuboniwa H, Tjandra N, Grzesiek S, Ren H, Klee CB, Bax A. Solution structure of calcium-free calmodulin. Nat Struct Biol. 1995 Sep;2(9):768-76. PMID:7552748
  3. ↑ 3.0 3.1 Babu YS, Bugg CE, Cook WJ. Structure of calmodulin refined at 2.2 A resolution. J Mol Biol. 1988 Nov 5;204(1):191-204. PMID:3145979
  4. ↑ Berridge MJ, Bootman MD, Roderick HL. Calcium signalling: dynamics, homeostasis and remodelling. Nat Rev Mol Cell Biol. 2003 Jul;4(7):517-29. PMID:12838335 doi:10.1038/nrm1155