The eukaryotic like-Sm (LSm) proteins assemble into a hetero-heptameric rings (LSm2-8 or LSm1-7) around a wide spectrum of RNAs. The LSm2-8 ring functions during general RNA maturation in the nucleus, while the LSm1-7 ring functions during mRNA degradation in the cytoplasm [, ]. LSm2-8 form the core of the U6 snRNP particle that, in turn, assembles with other components to form the spliceosome which is responsible for the excision of introns and the ligation of exons [, ]. The LSm1-7 ring is involved in recognition of the 3' uridylation tag and recruitment of the decapping machinery [, ].Members of the LSm family share a highly conserved Sm fold containing an N-terminal helix followed by a strongly bent five-stranded antiparallel β-sheet [].This entry represents LSm5.
