Accessibility of Myofilament Cysteines and Effects on ATPase Depend on the Activation State during Exposure to Oxidants
Figure 3
Structures predict accessibility of myofilament cysteines to solvent.
A. Location of cysteines in a tropomyosin heterodimer. The structure shown is the alpha homodimer (PDB structure: 2B9C), with the blue strand labeled to indicate locations of cysteines in the alpha isoform. B. Cysteine locations in one monomer of F-actin (PDB: 2ZWH) C. Location of cysteines in the fast muscle isoform of MHC (PDB: 2MYS). Cysteine numbering in MHC is based on rat MYH4 D,E. Locations of cysteines in cardiac (D) and fast (E) skeletal isoforms of troponin (TnC:Blue, TnI:Red, TnT:Green) (Cardiac troponin is PDB:1J1E; Fast skeletal troponin is PDB: 1YTZ). For comparison, cysteines in slow (s), cardiac (c) and fast (f) isoforms are labeled in each structure. Relative surface accessibility (RSA) values of cysteines are shown below the structures.
