Actin

Actin filaments are 7 nm fibres. They are present in both muscle's and they are a component of the cytoskeleton.

Structure:

• Thin
• Flexible
  

These filaments help to maintain cell shape.

Actin hydrolyzes ATP to ADP when ATP is bound to the nucleotide binding site, changing the conformation of actin. Actin filaments are polarized, and facillitate the movement of cellular components.