The 15.5-kD protein and its yeast homolog Snu13p bind U4 snRNA, U3 snoRNA, and the C/D box snoRNAs. In U4 snRNA, they associate with a helix-bulge-helix (K-turn) structure. U3 snoRNA contains two conserved pairs of boxes, C'/D and B/C, which were both expected to bind the 15.5-kD/Snu13 protein. Only binding to the B/C motif was experimentally demonstrated. Here, by chemical probing of in vitro reconstituted RNA/protein complexes, we demonstrate the independent binding of the 15.5-kD/Snu13 protein to each of the two motifs. Due to a highly reduced stem I (1 bp), the K-turn structure is not formed in the naked B/C motif. However, gel-shift experiments revealed a higher affinity of Snu13p for the B/C motif, compared to the C'/D motif. A phylogenetic analysis of U3 snoRNA, coupled with an analysis of Snu13p affinity for variant yeast C'/D and B/C motifs, and a study of the functionality of a truncated yeast U3 snoRNA carrying base substitutions in the C'/D and B/C motifs, revealed that conservation of the identities of residues 2 and 3 in the B/C K-turn is more important for Snu13p binding and U3 snoRNA function, than conservation of the identities of corresponding residues in the C'/D K-turn. This suggests that binding of Snu13p to K-turns with a very short helix I imposes sequence constraints in the bulge. Altogether, the data demonstrate the strong importance of the binding of the 15.5-kD/Snu13 protein to the C'/D and B/C motifs for both U3 snoRNP assembly and activity.
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http://purl.uniprot.org/cit... | rdf:type | uniprot:Journal_Citation | lld:uniprot |
http://purl.uniprot.org/cit... | rdfs:comment | The 15.5-kD protein and its yeast homolog Snu13p bind U4 snRNA, U3 snoRNA, and the C/D box snoRNAs. In U4 snRNA, they associate with a helix-bulge-helix (K-turn) structure. U3 snoRNA contains two conserved pairs of boxes, C'/D and B/C, which were both expected to bind the 15.5-kD/Snu13 protein. Only binding to the B/C motif was experimentally demonstrated. Here, by chemical probing of in vitro reconstituted RNA/protein complexes, we demonstrate the independent binding of the 15.5-kD/Snu13 protein to each of the two motifs. Due to a highly reduced stem I (1 bp), the K-turn structure is not formed in the naked B/C motif. However, gel-shift experiments revealed a higher affinity of Snu13p for the B/C motif, compared to the C'/D motif. A phylogenetic analysis of U3 snoRNA, coupled with an analysis of Snu13p affinity for variant yeast C'/D and B/C motifs, and a study of the functionality of a truncated yeast U3 snoRNA carrying base substitutions in the C'/D and B/C motifs, revealed that conservation of the identities of residues 2 and 3 in the B/C K-turn is more important for Snu13p binding and U3 snoRNA function, than conservation of the identities of corresponding residues in the C'/D K-turn. This suggests that binding of Snu13p to K-turns with a very short helix I imposes sequence constraints in the bulge. Altogether, the data demonstrate the strong importance of the binding of the 15.5-kD/Snu13 protein to the C'/D and B/C motifs for both U3 snoRNP assembly and activity. | lld:uniprot |
http://purl.uniprot.org/cit... | skos:exactMatch | http://purl.uniprot.org/pub... | lld:uniprot |
http://purl.uniprot.org/cit... | uniprot:name | RNA | lld:uniprot |
http://purl.uniprot.org/cit... | uniprot:author | Branlant C. | lld:uniprot |
http://purl.uniprot.org/cit... | uniprot:author | Charpentier B. | lld:uniprot |
http://purl.uniprot.org/cit... | uniprot:author | Marmier-Gourrier N. | lld:uniprot |
http://purl.uniprot.org/cit... | uniprot:author | Clery A. | lld:uniprot |
http://purl.uniprot.org/cit... | uniprot:author | Senty-Segault V. | lld:uniprot |
http://purl.uniprot.org/cit... | uniprot:author | Schlotter F. | lld:uniprot |
http://purl.uniprot.org/cit... | uniprot:author | Leclerc F. | lld:uniprot |
http://purl.uniprot.org/cit... | uniprot:author | Fournier R. | lld:uniprot |
http://purl.uniprot.org/cit... | uniprot:date | 2003 | lld:uniprot |
http://purl.uniprot.org/cit... | uniprot:pages | 821-838 | lld:uniprot |
http://purl.uniprot.org/cit... | uniprot:title | A structural, phylogenetic, and functional study of 15.5-kD/Snu13 protein binding on U3 small nucleolar RNA. | lld:uniprot |
http://purl.uniprot.org/cit... | uniprot:volume | 9 | lld:uniprot |
http://purl.uniprot.org/cit... | dc-term:identifier | doi:10.1261/rna.2130503 | lld:uniprot |
uniprot-protein:P39990 | uniprot:citation | http://purl.uniprot.org/cit... | lld:uniprot |
http://linkedlifedata.com/r... | rdf:object | http://purl.uniprot.org/cit... | lld:uniprot |