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U4atac minor spliceosomal RNA

U4atac minor spliceosomal RNA is a ncRNA which is an essential component of the minor U12-type spliceosome complex. The U12-type spliceosome is required for removal of the rarer class of eukaryotic introns (AT-AC, U12-type).[1]

U4atac minor spliceosomal RNA
Other data
RNA typeGene; snRNA; splicing
GO0000355 0000369 0030624 0030627 0005690
PDB structuresPDBe

U4atac snRNA is proposed to form a base-paired complex with another spliceosomal RNA U6atac via two stem loop regions. These interacting stem loops have been shown to be required for in vivo splicing.[2] U4atac also contains a 3' Sm protein binding site which has been shown to be essential for splicing activity.[2] U4atac is the functional analog of U4 spliceosomal RNA in the major U2-type spliceosomal complex.[2]

The Drosophila U4atac snRNA has an additional predicted 3' stem loop terminal to the Sm binding site.[3]


It has been shown that mutations in the U4atac snRNA can cause microcephalic osteodysplastic primordial dwarfism type I (MOPD I), also called Taybi-Linder syndrome (TALS). MOPD I is a developmental disorder that is associated with brain and skeletal abnormalities. It has been shown that the mutations cause defective U12 splicing.[4][5]


  1. ^ Lorkovic ZJ, Lehner R, Forstner C, Barta A (2005). "Evolutionary conservation of minor U12-type spliceosome between plants and humans". RNA. 11 (7): 1095–1107. doi:10.1261/rna.2440305. PMC 1370794. PMID 15987817.
  2. ^ a b c Shukla GC, Cole AJ, Dietrich RC, Padgett RA (2002). "Domains of human U4atac snRNA required for U12-dependent splicing in vivo". Nucleic Acids Res. 30 (21): 4650–4657. doi:10.1093/nar/gkf609. PMC 135832. PMID 12409455.
  3. ^ Padgett RA, Shukla GC (2002). "A revised model for U4atac/U6atac snRNA base pairing". RNA. 8 (2): 125–128. doi:10.1017/S1355838202017156. PMC 1370236. PMID 11911359.
  4. ^ He, H; et al. (2011). "Mutations in U4atac snRNA, a Component of the Minor Spliceosome, in the Developmental Disorder MOPD I". Science. 332 (6026): 238–240. doi:10.1126/science.1200587. PMC 3380448. PMID 21474760.
  5. ^ Edery, P; et al. (2011). "Association of TALS developmental disorder with defect in minor splicing component U4atac snRNA". Science. 332 (6026): 240–243. doi:10.1126/science.1202205. PMID 21474761.

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