InterPro domain: IPR034146

This entry represents the RNA recognition motif (RRM) of snRNP35 (also known as U11/U12-35K), which is one of the components of the U11/U12 snRNP, a spliceosome required for splicing U12-type nuclear pre-mRNA introns [ 1 , 2 ].

U11/U12-35K is highly conserved among bilateria and plants, but is lacking in some organisms, such as Saccharomyces cerevisiae and Caenorhabditis elegans. Moreover, U11/U12-35K shows significant sequence similarity to U1 snRNP-specific 70kDa protein (U1-70K or snRNP70) [ 3 ].

U11/U12-35K contains a conserved RNA recognition motif (RRM), followed by an adjacent glycine-rich region, and an Arg-Asp and Arg-Glu dipeptide repeat-rich domain, making U11/U12-35K a possible functional analogue of U1-70K. It may facilitate 5' splice site recognition in the minor spliceosome and play a role in exon bridging, interacting with components of the major spliceosome bound to the pyrimidine tract of an upstream U2-type intron [ 4 , 5 ].

1. The human 18S U11/U12 snRNP contains a set of novel proteins not found in the U2-dependent spliceosome. RNA 10, 929-41
2. Identification of both shared and distinct proteins in the major and minor spliceosomes. Science 284, 2003-5
3. Cloning and characterization of a family of cDNAs from human histiocyte macrophage cells encoding an arginine-rich basic protein related to the 70 kD U1-snRNP splicing factor. DNA Seq. 9, 205-15
4. Dynamics in multi-domain protein recognition of RNA. Curr. Opin. Struct. Biol. 22, 287-96
5. Structural insight into RNA recognition motifs: versatile molecular Lego building blocks for biological systems. Wiley Interdiscip Rev RNA 3, 229-46