Crystal structure of the spliceosomal U2B"-U2A' protein complex bound to a fragment of U2 small nuclear RNA.
We have determined the crystal structure at 2.4 A resolution of a ternary complex between the spliceosomal U2B"/U2A' protein complex and hairpin-loop IV of U2 small nuclear RNA. Unlike its close homologue the U1A protein, U2B" binds to its cognate RNA only in the presence of U2A', which contains leucine-rich repeats in its sequence. The concave surface of a parallel beta-sheet within the leucine-rich-repeat region of U2A' interacts with the ribonucleoprotein domain of U2B" on the surface opposite its RNA-binding surface. The basic carboxy-terminal region of U2A' interacts with the RNA stem. The crystal structure reveals how protein-protein interaction regulates RNA-binding specificity, and how replacing only a few key residues allows the U2B" and U1A proteins to discriminate between their cognate RNA hairpins by forming alternative networks of interactions.
Price
S R
SR
MRC Laboratory of Molecular Biology, Cambridge, UK.
Evans
P R
PR
Nagai
K
K
D000595:Amino Acid Sequence; D000818:Animals; D001324:Autoantigens; D018360:Crystallography, X-Ray; D004330:Drosophila; D029721:Drosophila Proteins; D019143:Evolution, Molecular; D006801:Humans; D000090263:Leucine-Rich Repeat Proteins; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry; D012342:RNA, Small Nuclear / Q000737:chemistry* / Q000378:metabolism; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins / Q000737:chemistry; D017412:Ribonucleoprotein, U1 Small Nuclear / Q000737:chemistry; D017413:Ribonucleoprotein, U2 Small Nuclear / Q000737:chemistry* / Q000378:metabolism; D017411:Ribonucleoproteins, Small Nuclear; D055517:snRNP Core Proteins
D001324:Autoantigens; D029721:Drosophila Proteins; D000090263:Leucine-Rich Repeat Proteins; D011506:Proteins; D012342:RNA, Small Nuclear; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; D017412:Ribonucleoprotein, U1 Small Nuclear; D017413:Ribonucleoprotein, U2 Small Nuclear; D017411:Ribonucleoproteins, Small Nuclear; D055517:snRNP Core Proteins; C526408:SNRPB2 protein, human; C096026:U2A protein, Drosophila; C484318:SNRPA1 protein, human; C089969:snf protein, Drosophila