Actins are a highly conserved family of proteins found in virtually all eukaryotic cells. They have prolific roles in cell motility - from the contraction of striated muscle to the movement of organelles within cells, and are known to interact with a diverse number of proteins families from myosins to gelsolins. This up-to-date edition gives a comprehensive account of actin sequence, mutation and structure as well as providing insight into ligand-binding sites and drug and toxin binding. Illustrated throughout, this modern text also contains an extensive bibliography for the interested reader.