Homo sapiens U73A C/D box snoRNA. This snoRNA was characterized by Rebane et al. (1998) as a conserved sequence in intron 4 of the RPS3a gene. Its expression was evidenced in 4 cell lines by Northern blot analysis, and its 5’ end mapped by primer extension. It is predicted to guide the 2’O-ribose methylation of 28S rRNA G1747, although this base was not shown to be methylated. U73a and U73b share the same host gene.