Sandbox 213: Difference between revisions
Jump to navigation
Jump to search
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
<Structure load='3CLN' size='300' frame='true' align='left' caption='Calcium-bound calmodulin' scene='Insert optional scene name here' /> | <Structure load='3CLN' size='300' frame='true' align='left' caption='Calcium-bound calmodulin' scene='Insert optional scene name here' /> | ||
[[Calmodulin]] (CaM) for Calcium-Modulated protein is an important protein that intervenes in a wide range of activities | [[Calmodulin]] (CaM) for Calcium-Modulated protein is an important protein that intervenes in a wide range of activities<ref name="Najl V Valeyev1, Declan G Bates1, Pat Heslop-Harrison1,2, Ian Postlethwaite1 and Nikolay V Kotov. Elucidating the mechanisms of cooperative calcium-calmodulin interactions: a structural systems biology approach.BMC Systems Biology 2008, 2:48 doi:[[10.1186/1752-0509-2-48]]"/>. | ||
CaM is expressed in many cell types and can have different subcellular locations, including the cytoplasm, within organelles, or associated with the plasma or organelle membranes. | CaM is expressed in many cell types and can have different subcellular locations, including the cytoplasm, within organelles, or associated with the plasma or organelle membranes. | ||
| Line 35: | Line 35: | ||
Calmodulin contains four Ca<sup>2+</sup> binding sites and the binding of calcium induces a conformational change in calmodulin that can cause the activation of key enzymes such as kinases or phosphatases proteins (especially phosphorylase kinases) which are not necessarily themselves Ca<sup>2+</sup>-sensitive and allows a large diversity of cellular response. | Calmodulin contains four Ca<sup>2+</sup> binding sites and the binding of calcium induces a conformational change in calmodulin that can cause the activation of key enzymes such as kinases or phosphatases proteins (especially phosphorylase kinases) which are not necessarily themselves Ca<sup>2+</sup>-sensitive and allows a large diversity of cellular response. | ||
The calmodulin structure has been determined by NMR. This method reveals that calmodulin is a long molecule which looks like a '''dumbbell''' because it contains '''two globular domains''' (the <scene name='Sandbox_213/N-lobe/1'>N-lobe</scene> and the <scene name='Sandbox_213/C-lobe/1'>C-lobe</scene>) linked by a <scene name='Sandbox_213/flexible α-helix/1'>flexible α-helix</scene>. | The calmodulin structure has been determined by NMR. This method reveals that calmodulin is a long molecule which looks like a '''dumbbell''' because it contains '''two globular domains''' (the <scene name='Sandbox_213/N-lobe/1'>N-lobe</scene> and the <scene name='Sandbox_213/C-lobe/1'>C-lobe</scene>) linked by a <scene name='Sandbox_213/flexible α-helix/1'>flexible α-helix</scene> <ref name="Najl V Valeyev1, Declan G Bates1, Pat Heslop-Harrison1,2, Ian Postlethwaite1 and Nikolay V Kotov. Elucidating the mechanisms of cooperative calcium-calmodulin interactions: a structural systems biology approach.BMC Systems Biology 2008, 2:48 doi:[[10.1186/1752-0509-2-48]]"/>. | ||
Each lobe contains a pair of <scene name='Sandbox_213/helix-loop-helix/1'>helix-loop-helix</scene> motifs (called EF-hand or calmodulin-fold) that can bind two Ca<sup>2+</sup> ions. However those lobes do not have the same properties because the C-lobe has higher Ca<sup>2+</sup> affinity than the N-lobe. | Each lobe contains a pair of <scene name='Sandbox_213/helix-loop-helix/1'>helix-loop-helix</scene> motifs (called EF-hand or calmodulin-fold) that can bind two Ca<sup>2+</sup> ions. However those lobes do not have the same properties because the C-lobe has higher Ca<sup>2+</sup> affinity than the N-lobe. | ||
The two EF-hands are located in the vicinity of each other. Those neighboring sited are very likely to structurally influence each other upon Ca<sup>2+</sup> binding to one of them. | The two EF-hands are located in the vicinity of each other. Those neighboring sited are very likely to structurally influence each other upon Ca<sup>2+</sup> binding to one of them. | ||