troponin

Function

• thin filament regulatory complex which confers Ca+2 sensitivity to striated muscle actomyosin ATPase activity
• Ca+2 controls muscle contraction by an allosteric mechanism in which the flow of information is: Ca+2 -> troponin -> tropomyosin -> actin -> myosin

Structure

• troponin is a trimeric complex of:
  • troponin-C
  • troponin-I
  • troponin-T

Compartment

• located in thin muscle filaments at intervals of 38.5 nm, a period set by tropomyosin

More general terms

• cytoskeletal protein
• contractile protein
• multisubunit protein