1.
Proteins of the U1, U2, and U11/U12 snRNPs
| 12S U1 | 17S U2 | 18S U11/U12 | Functions (with Selected References) |
|---|---|---|---|
| Sm proteins1 | Sm proteins1 | Sm proteins1 | snRNP core components26 |
| U1-A (SNRPA) | Structural; RNA-binding37 | ||
| U1-C (SNRPC) | 5′ss recognition37 | ||
| U1-70K (SNRNP70) | Structural; SR protein interactions37,38 | ||
| U2A′ (SNRPA1) | Structural; RNA-binding | ||
| U2B′′ (SNRPB2) | Structural; RNA-binding | ||
| SF3a complex2 | BPS binding39 | ||
| SF3b complex2 | SF3b complex2 | BPS binding33,39 | |
| 20K (ZMAT5) | Unknown; homology to U1C32 | ||
| 25K (SNRNP25) | Unknown | ||
| 31K (ZCRB1) | Unknown; RNA-binding40 | ||
| 35K (SNRNP35) | SR protein interactions, homology to U1-70K33,41,42 | ||
| 48K (SNRNP48) | 5′ss recognition43 | ||
| 59K (PDCD7) | Structural, binds 48K and 65K43,44 | ||
| 65K (RNPC3) | Structural, binds U12 snRNA44 | ||
| Urp3 (ZRSR2) | 3′ss recognition45 | ||
| hPrp434 | hPrp43 (DHX15) | ||
| Y Box-13 (YBX1) |
The Hugo names of proteins have been provided in parentheses.
1
Sm proteins B/B', D1, D2, D3, E, F, and G,
2
Multi-subunit complexes.
3
Also present in the major spliceosome, but not in U1 or U2 snRNPs.
4
Almost stoichiometric presence in the 17S U2. Other proteins associated with U2 in substoichiometric amounts are omitted.46