Structural highlights
Function
[TNNC2_CHICK] Troponin is the central regulatory protein of striated muscle contraction. Tn consists of three components: Tn-I which is the inhibitor of actomyosin ATPase, Tn-T which contains the binding site for tropomyosin and Tn-C. The binding of calcium to Tn-C abolishes the inhibitory action of Tn on actin filaments.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
We have solved and refined the crystal and molecular structures of the calcium-saturated N-terminal domain of troponin C (TnC) to 1.75 A resolution. This has allowed for the first detailed analysis of the calcium binding sites of this molecular switch in the calcium-loaded state. The results provide support for the proposed binding order and qualitatively, for the affinity of calcium in the two regulatory calcium binding sites. Based on a comparison with the high-resolution apo-form of TnC we propose a possible mechanism for the calcium-mediated exposure of a large hydrophobic surface that is central to the initiation of muscle contraction within the cell.
Structural details of a calcium-induced molecular switch: X-ray crystallographic analysis of the calcium-saturated N-terminal domain of troponin C at 1.75 A resolution.,Strynadka NC, Cherney M, Sielecki AR, Li MX, Smillie LB, James MN J Mol Biol. 1997 Oct 17;273(1):238-55. PMID:9367759[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Strynadka NC, Cherney M, Sielecki AR, Li MX, Smillie LB, James MN. Structural details of a calcium-induced molecular switch: X-ray crystallographic analysis of the calcium-saturated N-terminal domain of troponin C at 1.75 A resolution. J Mol Biol. 1997 Oct 17;273(1):238-55. PMID:9367759 doi:http://dx.doi.org/10.1006/jmbi.1997.1257
