FMNL3 FH2–actin structure gives insight into formin-mediated actin nucleation and elongation

Formins regulate actin nucleation and filament elongation through their conserved FH2 domain. The formin FMNL3 induces assembly of filopodia, and now the crystal structure of its FH2 domain in complex with actin, together with functional analyses, provides insight into formin's activities.