This gene is located in the surfeit gene cluster, a group of very tightly linked housekeeping genes that do not share sequence similarity. The gene is oriented in a head-to-head fashion with RPL7A (SURF3) and the two genes share a bidirectional promoter. The encoded proteins are localized to the cytoplasm. Two alternative transcript variants encoding different isoforms have been identified for this gene.Synonyms: Mediator complex subunit 22, Mediator of RNA polymerase II transcription subunit 22, Surf-5, Surfeit locus protein 5