9.5 - Microfilaments
- Composed of globular subunits of protein actin.
- Entire microfilament has a polarity.
- Have dynamic properties
- Actin filaments will interact in a highly specific manner with the protein myosin.
Before it is incorporated into a filament, an actin monomer binds a molecule of ATP.
Assembly depends on concentration of actin monomers.
- Myosins move towards the plus end of an actin filament.
- Head consists of a site that binds an actin filament and site that binds and hydrolyses
ATP to drive the myosin motor.
- 2 groups
o Conventional Myosins (Type II)