Required for pre-18S rRNA processing. May bind microtubules. Interacts with SIK1/NOP56 and NOP1. Interacts with the trimethylguanosine synthase TGS1. Component of the ribosomal small subunit (SSU) processome composed of at least 40 protein subunits and snoRNA U3. Present with 34700 molecules/cell in log phase SD medium. Belongs to the NOP5/NOP56 family.