| U4 spliceosomal RNA | |
|---|---|
 Predicted secondary structure and sequence conservation of U4 | |
| Identifiers | |
| Symbol | U4 |
| Rfam | RF00015 |
| Other data | |
| RNA type | Gene; snRNA; splicing |
| Domain(s) | Eukaryota |
| GO | GO:0017070 GO:0000353 GO:0000351 GO:0005687 GO:0046540 |
| SO | SO:0000393 |
| PDB structures | PDBe |
The U4 small nuclear Ribo-Nucleic Acid (U4 snRNA) is a non-coding RNA component of the major or U2-dependent spliceosome – a eukaryotic molecular machine involved in the splicing of pre-messenger RNA (pre-mRNA). It forms a duplex with U6, and with each splicing round, it is displaced from the U6 snRNA (and the spliceosome) in an ATP-dependent manner, allowing U6 to re-fold and create the active site for splicing catalysis. A recycling process involving protein Brr2 releases U4 from U6, while protein Prp24 re-anneals U4 and U6. The crystal structure of a 5′ stem-loop of U4 in complex with a binding protein has been solved.[1]
- ^ a b Vidovic I, Nottrott S, Hartmuth K, Lührmann R, Ficner R (December 2000). "Crystal structure of the spliceosomal 15.5kD protein bound to a U4 snRNA fragment". Mol. Cell. 6 (6): 1331–42. doi:10.1016/S1097-2765(00)00131-3. hdl:11858/00-001M-0000-0012-F75C-F. PMID 11163207.