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

Role of Troponin C in decreased muscle sensitivity to calcium

Human Cardiac Troponin C
Human Cardiac Troponin C in complex with the Green Tea Polyphenol

TnT binds to tropomyosin.
TnI binds to actin which is found in thin muscle filaments.

Disease

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

3D Structures of Troponin3D Structures of Troponin

Updated on 12-October-2017

Troponin C+Troponin I+Troponin T
- 2w49, 2w4u – cTnC+cTnI+cTnT+tropomyosin+actin – chicken
- 1ytz - cTnC+cTnI+cTnT+Ca
- 1yv0 - cTnC+cTnI+cTnT
- 1j1d, 1j1e, 4y99 – hTnC (mutant)+hTnI (mutant) fragment+hTnT fragment+Ca - human
Troponin C+Troponin I
- 2krd, 2mkp – hTnC+hTnI + Ca – NMR
- 1ozs - hTnC C-terminal+hTnI N-terminal – NMR
- 2l1r - hTnC C-terminal+hTnI switch region - NMR
- 1lxf, 1mxl - hTnC N-terminal+hTnI fragment - NMR
- 2n7l - hTnC N-terminal/hTnC switch + drug analog – NMR
- 2kgb – hTnC (mutant) regulatory domain+TnI - NMR
- 2mzp - hTnC regulatory domain+TnI switch region (mutant) - NMR
- 1sbj – cTnC C-terminal+cTnI N-terminal+Mg - NMR
- 1scv, 1fi5, 1blq - cTnC C-terminal+cTnI N-terminal – NMR
- 1npq - cTnC (mutant) N-terminal+cTnI fragment+rhodamine
- 1jc2 - cTnC C-terminal+cTnI N-terminal
- 1a2x - rTnC +rTnI fragment – rabbit
- 3tz1 - TnC C terminal +TnI fragment – akazara scallop
Troponin C
- 2kdh – hTnC+green tea polyphenol – NMR
- 2jt0, 2jtz, 2jt8, 2jt3 – hTnC (mutant) – NMR
- 3rv5, 3sd6, 3swb, 4gje, 1spy - hTnC N-terminal
- 4gjg, 5vln - hTnC N-terminal (mutant)
- 1ap4 - hTnC N-terminal+Ca – NMR
- 2jxl, 2n79 - hTnC N-terminal (mutant) + Ca – NMR
- 4gjf - hTnC N-terminal (mutant) + Cd
- 1wrk, 1wrl - hTnC N-terminal (mutant) +trifluoperazine
- 5w88, 5wcl - hTnC N-terminal (mutant) + methyldiphenylamine - NMR
- 2kfx – hTnC (mutant) N-terminal+Ca+naphthalene derivative
- 2mle - hTnC C-terminal – NMR
- 2mlf - hTnC C-terminal (mutant) – NMR
- 1ih0 - hTnC C-terminal+EMD 57033 – NMR
- 2l98 – hTnC EF-hand domains 3,4 + resveratrol
- 1la0, 4tnc – cTnC+Ca
- 1dtl – cTnC (mutant)+Ca +bepridil
- 1skt, 1zac, 2ctn - cTnC N-terminal – NMR
- 1aj4 - cTnC (mutant) +Ca – NMR
- 3ctn - cTnC C-terminal – NMR
- 1avs - cTnC N-terminal+Ca
- 1smg, 1tnq - cTnC N-terminal+Ca - NMR
- 1ncy – cTnC+Mn
- 1ncx, 1ncz, 1top – cTnC
- 1pon, 1cta, 1ctd – cTnC fragment – NMR
- 1tnp - cTnC N-terminal – NMR
- 1tnw, 1tnx - cTnC +Ca - NMR
- 1trf - tTnC N-terminal+Ca - turkey – NMR
- 5tnc - tTnC
- 2k2a - TnC C-terminal – Lethocerus indicus – NMR
- 2jnf – TnC – fly – NMR
- 1r2u, 1r6p - TnC N-terminal – trout – NMR
- 1tcf – rTnC+Ca
- 1tn4, 2tn4 – rTnC (mutant)+Ca
Troponin I
- 2jpw – TnI biphosphorylated – mouse – NMR
- 1vdi – cTnI – NMR
- 1vdj – cTnI+Ca - NMR
Troponin T
- 2z5h – yTnT fragment+tropomyosin – yeast

ReferencesReferences

↑ 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

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Alexander Berchansky, Michal Harel, Joel L. Sussman

[1] 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

[2] 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

[3] 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

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