Small nuclear ribonucleoprotein G (IPR034098)

Short name: Sm_G

Overlapping homologous superfamilies

Family relationships



This entry represents the small nuclear ribonucleoprotein G.

The eukaryotic Sm proteins (B/B', D1, D2, D3, E, F and G) assemble into a hetero-heptameric ring around the Sm site of the 2,2,7-trimethyl guanosine (m3G) capped U1, U2, U4 and U5 snRNAs (Sm snRNAs) forming the core of the snRNP particle [PMID: 11226169]. The snRNP particle, in turn, assembles with other components onto the pre-mRNA to form the spliceosome which is responsible for the excision of introns and the ligation of exons. Members of this family share a highly conserved Sm fold containing an N-terminal helix followed by a strongly bent five-stranded antiparallel beta-sheet [PMID: 10025403]. Sm subunit G binds subunits E and F to form a trimer which then assembles onto snRNA along with the D1/D2 and D3/B heterodimers forming a seven-membered ring structure [PMID: 10369684, PMID: 11259661, PMID: 23333303].

GO terms

Biological Process

GO:0000387 spliceosomal snRNP assembly

Molecular Function

No terms assigned in this category.

Cellular Component

GO:0005681 spliceosomal complex

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.