Troponin

Function

Troponin (Tn) is a regulatory protein in muscle contraction. It contains 3 subunits:

TnC causes conformational change in TnI when it binds to calcium ions^[1]. For more details on TnC see

TnT binds to tropomyosin.
TnI binds to actin which is found in thin muscle filaments. See Human Cardiac Troponin I

Mutations in TnI^[2] and TnT ^[3]are associated with hypertrophic cardiomyopathy.

Chicken troponin: subunit T (dark green), subunit I (wheat), subunit C (pink) complex with Mg+2 ion (green) 1yv0

Drag the structure with the mouse to rotate

↑ Li MX, Hwang PM. Structure and function of cardiac troponin C (TNNC1): Implications for heart failure, cardiomyopathies, and troponin modulating drugs. Gene. 2015 Oct 25;571(2):153-66. doi: 10.1016/j.gene.2015.07.074. Epub 2015 Jul, 29. PMID:26232335 doi:http://dx.doi.org/10.1016/j.gene.2015.07.074
↑ Kimura A, Harada H, Park JE, Nishi H, Satoh M, Takahashi M, Hiroi S, Sasaoka T, Ohbuchi N, Nakamura T, Koyanagi T, Hwang TH, Choo JA, Chung KS, Hasegawa A, Nagai R, Okazaki O, Nakamura H, Matsuzaki M, Sakamoto T, Toshima H, Koga Y, Imaizumi T, Sasazuki T. Mutations in the cardiac troponin I gene associated with hypertrophic cardiomyopathy. Nat Genet. 1997 Aug;16(4):379-82. PMID:9241277 doi:10.1038/ng0897-379
↑ Palm T, Graboski S, Hitchcock-DeGregori SE, Greenfield NJ. Disease-causing mutations in cardiac troponin T: identification of a critical tropomyosin-binding region. Biophys J. 2001 Nov;81(5):2827-37. PMID:11606294 doi:http://dx.doi.org/10.1016/S0006-3495(01)75924-3