Component of the UAF (upstream activation factor) complex which interacts with the upstream element of the RNA polymerase I promoter and forms a stable preinitiation complex. UAF seems to stimulate basal transcription to a fully activated level. Component of the UAF (upstream activation factor) complex which consists of spp27/uaf30, rrn5, rrn10, and histones H3 and H4. Interacts with rrn10.