Gem-associated protein 6 (Gemin-6) (SIP2)
1_MSEWM 6_ KKGPL 11_ EWQDY 16_ IYKEV 21_ RVTAS 26_ EKNEY 31_ KGWVL 36_ TTDPV 41_ SANIV 46_ LVNFL 51_ EDGSM 56_ SVTGI 61_ MGHAV 66_ QTVET 71_ MNEGD 76_ HRVRE 81_ KLMHL 86_ FTSGD 91_ CKAYS 96_ PEDLE 101_ ERKNS 106_ LKKWL 111_ EKNHI 116_ PITEQ 121_ GDAPR 126_ TLCVA 131_ GVLTI 136_ DPPYG 141_ PENCS 146_ SSNEI 151_ ILSRV 156_ QDLIE 161_GHLTA
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. 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). In the cytosol, the Sm proteins SNRPD1, SNRPD2, SNRPE, SNRPF and SNRPG are trapped in an inactive 6S pICln-Sm complex by the chaperone CLNS1A that controls the assembly of the core snRNP. To assemble core snRNPs, the SMN complex accepts the trapped 5Sm proteins from CLNS1A forming an intermediate. Binding of snRNA inside 5Sm triggers eviction of the SMN complex, thereby allowing binding of SNRPD3 and SNRPB to complete assembly of the core snRNP