Myosin heavy chain that is required for the cell cycle-regulated transport of various organelles and proteins for their segregation. Functions by binding with its tail domain to receptor proteins on organelles and exerting force with its N-terminal motor domain against actin filaments, thereby transporting its cargo along polarized actin cables. Involved in trafficking of Golgi stacks and mitochondria. Homodimer. IQ domain mediates interaction with calmodulin. The tail domain is a globular cargo-binding domain. Belongs to the TRAFAC class myosin-kinesin ATPase superfamily. Myosin family. Plant myosin class XI subfamily. The predicted gene has been split into 2 genes: At1g08720 and At1g08730.