B MF assembly and disassembly Characteristics: (I)Within a me, all the actin monomers are oriented in the same direction, so MF has a polarity Light chains Minus end Myosin ..ooooo.o Myosin is (a) Bret treatment with trypsin Hinge egion Heads Actn molecular motor for 。4+ Myosin segmen actins Tht meromyosin Heavy meromyosin (b)Further treatment with trypsin Subfragment 1 Subfragment 2 (s2) Plus end 025m Plus(barbed)end Subfragment 1 (c) EM and diagram of S1 fragments'decoratingactin microfilamentsB. MF assembly and disassembly ❖Characteristics: (1) Within a MF, all the actin monomers are oriented in the same direction, so MF has a polarity Myosin is molecular motor for actins