DEAD-box RNA helicase-like protein required for pre-18S rRNA processing, specifically at sites A0, A1, and A2 (By similarity). Involved in the control of rRNA expression (PubMed:20877469). Required for embryo development and female gametogenesis (PubMed:20877469). Component of the ribosomal small subunit (SSU) processome composed of at least 40 protein subunits and snoRNA U3 (By similarity). Interacts with THAL in the nucleus (PubMed:27792779). Preferentially expressed in differentiating cells in young tissues such as floral buds, ovules, embryos, secondary roots, pollen, young seedlings and vascular bundles (PubMed:20877469). Observed ubiquitously (PubMed:20877469). Abnormal female gametogenesis and altered embryo development with a disturbed cellular division pattern (PubMed:20877469). Increased rRNA expression and hypomethylation of rRNA promoters (PubMed:20877469). Belongs to the UTP25 family.