1scv: Difference between revisions
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|PDB= 1scv |SIZE=350|CAPTION= <scene name='initialview01'>1scv</scene> | |PDB= 1scv |SIZE=350|CAPTION= <scene name='initialview01'>1scv</scene> | ||
|SITE= | |SITE= | ||
|LIGAND= <scene name='pdbligand=CA:CALCIUM ION'>CA</scene> | |LIGAND= <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene> | ||
|ACTIVITY= | |ACTIVITY= | ||
|GENE= TNNC1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9031 Gallus gallus]) | |GENE= TNNC1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9031 Gallus gallus]) | ||
|DOMAIN= | |||
|RELATEDENTRY=[[1sbj|1SBJ]] | |||
|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1scv FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1scv OCA], [http://www.ebi.ac.uk/pdbsum/1scv PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1scv RCSB]</span> | |||
}} | }} | ||
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[[Category: Howarth, J W.]] | [[Category: Howarth, J W.]] | ||
[[Category: Rosevear, P R.]] | [[Category: Rosevear, P R.]] | ||
[[Category: calcium binding protein]] | [[Category: calcium binding protein]] | ||
[[Category: cardiac]] | [[Category: cardiac]] | ||
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[[Category: troponin c-troponin i interaction]] | [[Category: troponin c-troponin i interaction]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 23:40:20 2008'' | ||
Revision as of 23:40, 30 March 2008
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| Ligands: | |||||||
| Gene: | TNNC1 (Gallus gallus) | ||||||
| Related: | 1SBJ
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
NMR STRUCTURE OF THE C TERMINAL DOMAIN OF CARDIAC TROPONIN C BOUND TO THE N TERMINAL DOMAIN OF CARDIAC TROPONIN I
OverviewOverview
Cardiac troponin C (cTnC) is the Ca(2+)-binding component of the troponin complex and, as such, is the Ca(2+)-dependent switch in muscle contraction. This protein consists of two globular lobes, each containing a pair of EF-hand metal-binding sites, connected by a linker. In the N lobe, Ca(2+)-binding site I is inactive and Ca(2+)-binding site II is primarily responsible for initiation of muscle contraction. The C lobe contains Ca(2+)/Mg(2+)-binding sites III and IV, which bind Mg(2+) with lower affinity and play a structural as well as a secondary role in modulating the Ca(2+) signal. To understand the structural consequences of Ca(2+)/Mg(2+) exchange in the C lobe, we have determined the NMR solution structure of the Mg(2+)-loaded C lobe, cTnC(81-161), in a complex with the N domain of cardiac troponin I, cTnI(33-80), and compared it with a refined Ca(2+)-loaded structure. The overall tertiary structure of the Mg(2+)-loaded C lobe is very similar to that of the refined Ca(2+)-loaded structure as evidenced by the root-mean-square deviation of 0.94 A for all backbone atoms. While metal-dependent conformational changes are minimal, substitution of Mg(2+) for Ca(2+) is characterized by condensation of the C-terminal portion of the metal-binding loops with monodentate Mg(2+) ligation by the conserved Glu at position 12 and partial closure of the cTnI hydrophobic binding cleft around site IV. Thus, conformational plasticity in the Ca(2+)/Mg(2+)-dependent binding loops may represent a mechanism to modulate C-lobe cTnC interactions with the N domain of cTnI.
About this StructureAbout this Structure
1SCV is a Single protein structure of sequence from Gallus gallus. Full crystallographic information is available from OCA.
ReferenceReference
Structure of the Mg2+-loaded C-lobe of cardiac troponin C bound to the N-domain of cardiac troponin I: comparison with the Ca2+-loaded structure., Finley NL, Howarth JW, Rosevear PR, Biochemistry. 2004 Sep 14;43(36):11371-9. PMID:15350124
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