RBFA (ribosome binding factor A) is a mitochondrial RNA-binding protein essential for matoribosomal small subunit (SSU) biogenesis and maturation 1. The protein binds to helices 44 and 45 of the 12S mitochondrial rRNA through its N-terminal region and KH-like domain to facilitate dimethylation of two conserved adenines, a critical post-transcriptional modification 12. Unlike bacterial orthologs that promote 5' rRNA processing, human RBFA promotes dimethylation without being required for initial SSU assembly 1. The dimethylation is necessary for completing mt-rRNA maturation and regulating small and large subunit association into functional monomers, establishing mitoribosomal quality control 1. During sequential SSU assembly, RBFA undergoes a conformational change after METTL15-promoted rRNA maturation, which allows mtIF3 to occupy the subunit interface and permits mS37 to outcompete RBFA and complete assembly 3. This dynamic assembly mechanism links SSU maturation to translation initiation, establishing the catalytic human mitoribosome 3. RBFA dysfunction causes mitoribosomal instability and mitochondrial dysfunction, suggesting clinical relevance for mitochondrial disorders affecting oxidative phosphorylation 2. The evolutionary conservation of RBFA function between bacteria and mitochondria highlights fundamental ribosome assembly mechanisms across domains.