InterPro domain: IPR034104

This entry represents Sm-like protein Lsm1. It can be found in the cytoplasmic Lsm1-7 complex, which associates with deadenylated mRNA and promotes decapping in the 5'-3' mRNA decay pathway [ 1 , 2 ].

The Sm and the Lsm proteins, characterised by the Sm-domain, have RNA-related functions. The Sm heptamer ring associates with four (U1, U2, U4, U5) snRNPs, while Lsm2-8 heptamer is part of the U6 snRNP. Another Lsm heptameric complex, Lsm1-7, which differs from Lsm2-8 by one Lsm protein, functions in mRNA decapping, a crucial step in the mRNA degradation pathway [ 3 ].

1. Crystal structures of Lsm3, Lsm4 and Lsm5/6/7 from Schizosaccharomyces pombe. PLoS ONE 7, e36768
2. Functions of Lsm proteins in mRNA degradation and splicing. Curr. Opin. Cell Biol. 12, 346-50
3. Crystal structure and biochemical analysis of the heptameric Lsm1-7 complex. Cell Res. 24, 497-500