The reconstitution of microbial rocketing motility in vitro with purified p
roteins has recently established definitively that no myosin motor is requi
red for protrusion. Instead, actin polymerization, in conjunction with a sm
all number of proteins, is sufficient. A dendritic pattern of nucleation co
ntrolled by the Arp2/3 complex provides an efficient pushing force for lame
llipodial motility.