Forms a fork protection complex (FPC) with TOF1 which is required for chromosome segregation during meiosis and DNA damage repair. FPC coordinates leading and lagging strand synthesis and moves with the replication fork. FPC stabilizes replication forks in a configuration that is recognized by replication checkpoint sensors and protects stalled replication forks against the fork-releasing activity of RRM3 helicase. Component of the fork protection complex (FPC) consisting of TOF1 and CSM3. Present with 358 molecules/cell in log phase SD medium. Belongs to the CSM3 family.