LSM domain, eukaryotic/archaea-type (IPR001163)

Short name: LSM_dom_euk/arc

Overlapping homologous superfamilies

Domain relationships


This domain is found in Lsm (like-Sm) proteins, which have a core structure consisting of an open beta-barrel with an SH3-like topology.

Lsm (like-Sm) proteins have diverse functions, and are thought to be important modulators of RNA biogenesis and function [PMID: 10801455, PMID: 12438310]. The Sm proteins form part of specific small nuclear ribonucleoproteins (snRNPs) that are involved in the processing of pre-mRNAs to mature mRNAs, and are a major component of the eukaryotic spliceosome. Most snRNPs consist of seven Sm proteins (B/B', D1, D2, D3, E, F and G) arranged in a ring on a uridine-rich sequence (Sm site), plus a small nuclear RNA (snRNA) (either U1, U2, U5 or U4/6) [PMID: 15130578]. All Sm proteins contain a common sequence motif in two segments, Sm1 and Sm2, separated by a short variable linker [PMID: 7744013]. Other snRNPs, such as U7 snRNP, can contain different Lsm proteins.

Lsm proteins are also found in archaebacteria, which do not have any splicing apparatus, suggesting a more general role for Lsm proteins. Archaeal Lsm proteins have been shown to bind to small RNAs and are probably involved in many cellular processes [PMID: 20826804]. Archaeal Lsm proteins are likely to represent the ancestral Lsm domain [PMID: 11399068].

Contributing signatures

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