Positively regulates dimethylation of two adjacent adenosines in the loop of a conserved hairpin near the 3'-end of 18S rRNA (PubMed:25851604). Expressed in liver, lung, spleen and kidney. Weakly expressed in thymus, testis and ovary. Weakly or not expressed in heart, brain, skeletal muscle, placenta, pancreas, prostate, small intestine, colon and peripheral blood leukocytes. Belongs to the PNO1 family.