Acts in a DNA repair pathway for removal of UV-induced DNA damage that is distinct from classical nucleotide excision repair and in repair of ionizing radiation damage. Functions in homologous recombination repair of DNA double strand breaks and in recovery of stalled replication forks. Probably plays a role in structure. Component of the Smc5-Smc6 complex which consists of KRE29, MMS21, NSE1, NSE3, NSE4, NSE5, SMC5 and SMC6. The flexible hinge domain, which separates the large intramolecular coiled coil regions, allows the heterotypic interaction with the corresponding domain of SMC5, forming a V-shaped heterodimer. Present with 339 molecules/cell in log phase SD medium. Belongs to the SMC family. SMC6 subfamily.