The ActA family is found in Listeria and is associated with motility. ActA protein acts as a scaffold to assemble and activate host cell actin cytoskeletal factors at the bacterial surface, resulting in directional actin polymerisation and propulsion of the bacterium through the cytoplasm of the host cell [1,2].

1: Systematic mutational analysis of the amino-terminal domain of the Listeria monocytogenes ActA protein reveals novel functions in actin-based motility. Lauer P, Theriot JA, Skoble J, Welch MD, Portnoy DA; Mol Microbiol 2001;42:1163-1177. PMID:11886549

2: Intracellular induction of Listeria monocytogenes actA expression. Shetron-Rama LM, Marquis H, Bouwer HG, Freitag NE; Infect Immun 2002;70:1087-1096. PMID:11854187