Gem-associated protein 2 (Gemin-2) (Component of gems 2) (Survival of motor neuron protein-interacting protein 1) (SMN-interacting protein 1)
1_MRRAE 6_ LAGLK 11_ TMAWV 16_ PAESA 21_ VEELM 26_ PRLLP 31_ VEPCD 36_ LTEGF 41_ DPSVP 46_ PRTPQ 51_ EYLRR 56_ VQIEA 61_ AQCPD 66_ VVVAQ 71_ IDPKK 76_ LKRKQ 81_ SVNIS 86_ LSGCQ 91_ PAPEG 96_ YSPTL 101_ QWQQQ 106_ QVAQF 111_ STVRQ 116_ NVNKH 121_ RSHWK 126_ SQQLD 131_ SNVTM 136_ PKSED 141_ EEGWK 146_ KFCLG 151_ EKLCA 156_ DGAVG 161_ PATNE 166_ SPGID 171_ YVQIG 176_ FPPLL 181_ SIVSR 186_ MNQAT 191_ VTSVL 196_ EYLSN 201_ WFGER 206_ DFTPE 211_ LGRWL 216_ YALLA 221_ CLEKP 226_ LLPEA 231_ HSLIR 236_ QLARR 241_ CSEVR 246_ LLVDS 251_ KDDER 256_ VPALN 261_ LLICL 266_ VSRYF 271_DQRDL
1: The SMN complex catalyzes the assembly of small nuclear ribonucleoproteins (snRNPs), the building blocks of the spliceosome, and thereby plays an important role in the splicing of cellular pre-mRNAs (PubMed:18984161, PubMed:9323129). Most spliceosomal snRNPs contain a common set of Sm proteins SNRPB, SNRPD1, SNRPD2, SNRPD3, SNRPE, SNRPF and SNRPG that assemble in a heptameric protein ring on the Sm site of the small nuclear RNA to form the core snRNP (Sm core) (PubMed:18984161). In the cytosol, the Sm proteins SNRPD1, SNRPD2, SNRPE, SNRPF and SNRPG (5Sm) are trapped in an inactive 6S pICln-Sm complex by the chaperone CLNS1A that controls the assembly of the core snRNP (PubMed:18984161). To assemble core snRNPs, the SMN complex accepts the trapped 5Sm proteins from CLNS1A (PubMed:18984161, PubMed:9323129). Binding of snRNA inside 5Sm ultimately triggers eviction of the SMN complex, thereby allowing binding of SNRPD3 and SNRPB to complete assembly of the core snRNP (PubMed:31799625). Within the SMN complex, GEMIN2 constrains the conformation of 5Sm, thereby promoting 5Sm binding to snRNA containing the snRNP code (a nonameric Sm site and a 3'-adjacent stem-loop), thus preventing progression of assembly until a cognate substrate is bound (PubMed:16314521, PubMed:21816274, PubMed:31799625)