7KAA

NMR solution structures of tirasemtiv drug bound to a fast skeletal troponin C-troponin I complex


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 25 
  • Selection Criteria: structures with the lowest energy 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structural Basis of Tirasemtiv Activation of Fast Skeletal Muscle.

Li, M.X.Mercier, P.Hartman, J.J.Sykes, B.D.

(2021) J Med Chem 64: 3026-3034

  • DOI: https://doi.org/10.1021/acs.jmedchem.0c01412
  • Primary Citation of Related Structures:  
    7KAA

  • PubMed Abstract: 

    Troponin regulates the calcium-mediated activation of skeletal muscle. Muscle weakness in diseases such as amyotrophic lateral sclerosis and spinal muscular atrophy occurs from diminished neuromuscular output. The first direct fast skeletal troponin activator, tirasemtiv , amplifies the response of muscle to neuromuscular input. Tirasemtiv binds selectively and strongly to fast skeletal troponin, slowing the rate of calcium release and sensitizing muscle to calcium. We report the solution NMR structure of tirasemtiv bound to a fast skeletal troponin C-troponin I chimera. The structure reveals that tirasemtiv binds in a hydrophobic pocket between the regulatory domain of troponin C and the switch region of troponin I, which overlaps with that of Anapoe in the X-ray structure of skeletal troponin. Multiple interactions stabilize the troponin C-troponin I interface, increase the affinity of troponin C for the switch region of fast skeletal troponin I, and drive the equilibrium toward the active state.


  • Organizational Affiliation

    Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Troponin C, skeletal muscle,Troponin I, fast skeletal muscle chimera152Homo sapiensMutation(s): 0 
Gene Names: TNNC2TNNI2
UniProt & NIH Common Fund Data Resources
Find proteins for P48788 (Homo sapiens)
Explore P48788 
Go to UniProtKB:  P48788
PHAROS:  P48788
GTEx:  ENSG00000130598 
Find proteins for P02585 (Homo sapiens)
Explore P02585 
Go to UniProtKB:  P02585
PHAROS:  P02585
GTEx:  ENSG00000101470 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupsP48788P02585
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
W97 (Subject of Investigation/LOI)
Query on W97

Download Ideal Coordinates CCD File 
C [auth A]6-ethynyl-1-(pentan-3-yl)-1H-imidazo[4,5-b]pyrazin-2-ol
C12 H14 N4 O
RSQGZEAXODVTOL-UHFFFAOYSA-N
CA
Query on CA

Download Ideal Coordinates CCD File 
B [auth A]CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 25 
  • Selection Criteria: structures with the lowest energy 

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Canadian Institutes of Health Research (CIHR)Canada37769
American Heart AssociationCanadaG-14-0005884

Revision History  (Full details and data files)

  • Version 1.0: 2021-03-24
    Type: Initial release
  • Version 1.1: 2021-04-07
    Changes: Database references
  • Version 1.2: 2023-06-14
    Changes: Database references, Other