Homo sapiens U19 snoRNA.
This H/ACA box RNA was cloned by Kiss, Bortolin and Filipowicz (1996). Its role in guiding the pseudouridylation of residues U3741 and U3743 of 28S rRNA was evidenced by Ganot et al. (1997a) and Bortolin and Kiss (1998). The pseudouridylation of these residues was previously reported by Ofengand and Bakin (1997).
U19 could also guide the pseudouridylation of U3 snRNA U8 (Schattner et al., 2006), experimentally established for rat U3B snoRNA by Reddy et al. (1979).
U19 resides in the Matrin3 gene from human to opossum. U19-2 in the ATP6V0E gene is probably a primate-specific retroposon. A second paralogue, U19-3, resides in the TIMM23 gene from human to chicken and xenopus.In human and chimp, the TIMM23 gene and the snoRNA sequence appear duplicated (U19-3b).