RNA-binding nucleolar protein required for pre-rRNA processing. Component of the 90S pre-ribosome involved in production of 18S rRNA and assembly of small ribosomal subunit. Component of the pre-40S ribosome required for release from the nucleolus. Component of the 90S pre-ribosome. Component of the pre-40S ribosome. Present with 2930 molecules/cell in log phase SD medium. Belongs to the NOP9 family.