Blocks the elongation and depolymerization of the actin filaments at the pointed end. The Tmod/TM complex contributes to the formation of the short actin protofilament, which in turn defines the geometry of the membrane skeleton. May play an important role in regulating the organization of actin filaments by preferentially binding to a specific tropomyosin isoform at its N-terminus (By similarity). Binds to the N-terminus of isoforms 2/3 of TPM3 and to actin. In myofibrils with sarcomeric structure, localizes to the pointed end of actin thin filaments. Belongs to the tropomodulin family.