Recoverin, a calcium-activated myristoyl switch
From Proteopedia
(Difference between revisions)
(→Myristoyl Switch and Calcium - polishing) |
(→Myristoyl Switch and Calcium - polishing) |
||
| Line 7: | Line 7: | ||
==Myristoyl Switch and Calcium== | ==Myristoyl Switch and Calcium== | ||
| - | <applet load='Recoverin_linear_morph14.pdb' scene='Recoverin,_a_calcium-activated_myristoyl_switch/ | + | <applet load='Recoverin_linear_morph14.pdb' scene='Recoverin,_a_calcium-activated_myristoyl_switch/Recoverin_no_calcium/2' size='400' frame='true' align='right' caption='Recoverin: 1iku model 7 morphed to 1jsa model 9. <font color="#808080">Hydrophobic</font>, <font color="#ff00ff">Polar</font>.' /> |
Recoverin has a <scene name='Recoverin,_a_calcium-activated_myristoyl_switch/Recoverin_morph/5'>myristic acid</scene> (14-carbon saturated fatty acid, or a similar acyl moiety) covalently linked via an amide bond to its N-terminal glycine. In the absence of calcium, the <scene name='Recoverin,_a_calcium-activated_myristoyl_switch/Recoverin_no_calcium/1'>myristoyl group is buried</scene> in the N-terminal protein domain, surrounded on all sides by alpha helices that form a hydrophobic pocket. The binding of <scene name='Recoverin,_a_calcium-activated_myristoyl_switch/Recoverin_morph/6'>two calcium ions</scene> to each recoverin molecule induces a <scene name='Recoverin,_a_calcium-activated_myristoyl_switch/Recoverin_morph/1'>conformational change </scene> that extrudes the myristoyl and exposes some hydrophobic amino acids on the surface. This enables the molecule to bind to the lipid bilayers of the disc membranes. | Recoverin has a <scene name='Recoverin,_a_calcium-activated_myristoyl_switch/Recoverin_morph/5'>myristic acid</scene> (14-carbon saturated fatty acid, or a similar acyl moiety) covalently linked via an amide bond to its N-terminal glycine. In the absence of calcium, the <scene name='Recoverin,_a_calcium-activated_myristoyl_switch/Recoverin_no_calcium/1'>myristoyl group is buried</scene> in the N-terminal protein domain, surrounded on all sides by alpha helices that form a hydrophobic pocket. The binding of <scene name='Recoverin,_a_calcium-activated_myristoyl_switch/Recoverin_morph/6'>two calcium ions</scene> to each recoverin molecule induces a <scene name='Recoverin,_a_calcium-activated_myristoyl_switch/Recoverin_morph/1'>conformational change </scene> that extrudes the myristoyl and exposes some hydrophobic amino acids on the surface. This enables the molecule to bind to the lipid bilayers of the disc membranes. | ||
Revision as of 02:47, 17 June 2008
|
Function
Recoverin is a 23 kD protein that regulates recovery of the eye from exposure to light, and the adaptation to background light. Recoverin controls the lifetime of photoactivated rhodopsin. Recoverin in turn is regulated by calcium ions, which cause recoverin molecules to associate with the disc membranes which fill the photosensitive portion of the rod cells in the eye, rather than diffusing freely in the cytosol.
Myristoyl Switch and Calcium
| |||||||||||
Proteopedia Page Contributors and Editors (what is this?)
Eric Martz, Michal Harel, Karsten Theis, Alexander Berchansky, Joel L. Sussman, Eran Hodis
