1la0
From Proteopedia
(New page: 200px<br /><applet load="1la0" size="450" color="white" frame="true" align="right" spinBox="true" caption="1la0" /> '''Solution Structure of Calcium Saturated Card...) |
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'''Solution Structure of Calcium Saturated Cardiac Troponin C in the Troponin C-Troponin I Complex'''<br /> | '''Solution Structure of Calcium Saturated Cardiac Troponin C in the Troponin C-Troponin I Complex'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Cardiac troponin C (TnC) is composed of two globular domains connected by | + | Cardiac troponin C (TnC) is composed of two globular domains connected by a flexible linker. In solution, linker flexibility results in an ill defined orientation of the two globular domains relative to one another. We have previously shown a decrease in linker flexibility in response to cardiac troponin I (cTnI) binding. To investigate the relative orientation of calcium-saturated TnC domains when bound to cTnI, (1)H-(15)N residual dipolar couplings were measured in two different alignment media. Similarity in alignment tensor orientation for the two TnC domains supports restriction of domain motion in the presence of cTnI. The relative spatial orientation of TnC domains bound to TnI was calculated from measured residual dipolar couplings and long-range distance restraints utilizing a rigid body molecular dynamics protocol. The relative domain orientation is such that hydrophobic pockets face each other, forming a latch to constrain separate helical segments of TnI. We have utilized this structure to successfully explain the observed functional consequences of linker region deletion mutants. Together, these studies suggest that, although linker plasticity is important, the ability of TnC to function in muscle contraction can be correlated with a preferred domain orientation and interdomain distance. |
==About this Structure== | ==About this Structure== | ||
| - | 1LA0 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus] with CA as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1LA0 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus] with <scene name='pdbligand=CA:'>CA</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LA0 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Gallus gallus]] | [[Category: Gallus gallus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Abusamhadneh, E | + | [[Category: Abusamhadneh, E M.]] |
[[Category: Dvoretsky, A.]] | [[Category: Dvoretsky, A.]] | ||
| - | [[Category: Howarth, J | + | [[Category: Howarth, J W.]] |
| - | [[Category: Rosevear, P | + | [[Category: Rosevear, P R.]] |
[[Category: CA]] | [[Category: CA]] | ||
[[Category: ef-hand]] | [[Category: ef-hand]] | ||
[[Category: troponin]] | [[Category: troponin]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:43:04 2008'' |
Revision as of 11:43, 21 February 2008
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Solution Structure of Calcium Saturated Cardiac Troponin C in the Troponin C-Troponin I Complex
Overview
Cardiac troponin C (TnC) is composed of two globular domains connected by a flexible linker. In solution, linker flexibility results in an ill defined orientation of the two globular domains relative to one another. We have previously shown a decrease in linker flexibility in response to cardiac troponin I (cTnI) binding. To investigate the relative orientation of calcium-saturated TnC domains when bound to cTnI, (1)H-(15)N residual dipolar couplings were measured in two different alignment media. Similarity in alignment tensor orientation for the two TnC domains supports restriction of domain motion in the presence of cTnI. The relative spatial orientation of TnC domains bound to TnI was calculated from measured residual dipolar couplings and long-range distance restraints utilizing a rigid body molecular dynamics protocol. The relative domain orientation is such that hydrophobic pockets face each other, forming a latch to constrain separate helical segments of TnI. We have utilized this structure to successfully explain the observed functional consequences of linker region deletion mutants. Together, these studies suggest that, although linker plasticity is important, the ability of TnC to function in muscle contraction can be correlated with a preferred domain orientation and interdomain distance.
About this Structure
1LA0 is a Single protein structure of sequence from Gallus gallus with as ligand. Full crystallographic information is available from OCA.
Reference
Solution structure of calcium-saturated cardiac troponin C bound to cardiac troponin I., Dvoretsky A, Abusamhadneh EM, Howarth JW, Rosevear PR, J Biol Chem. 2002 Oct 11;277(41):38565-70. Epub 2002 Jul 29. PMID:12147696
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