Involved in nucleolar processing of pre-18S ribosomal RNA. Component of the ribosomal small subunit (SSU) processome composed of at least 40 protein subunits and snoRNA U3. Interacts with snoRNA U3. Interacts with EBP2, FAF1, MPP10, RPS16A and RRP14 (By similarity). Belongs to the UTP11 family.