1u6b
From Proteopedia
CRYSTAL STRUCTURE OF A SELF-SPLICING GROUP I INTRON WITH BOTH EXONS
Structural highlights
Function[SNRPA_HUMAN] Binds stem loop II of U1 snRNA. It is the first snRNP to interact with pre-mRNA. This interaction is required for the subsequent binding of U2 snRNP and the U4/U6/U5 tri-snRNP. In a snRNP-free form (SF-A) may be involved in coupled pre-mRNA splicing and polyadenylation process. Binds preferentially to the 5'-UGCAC-3' motif in vitro.[1] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe discovery of the RNA self-splicing group I intron provided the first demonstration that not all enzymes are proteins. Here we report the X-ray crystal structure (3.1-A resolution) of a complete group I bacterial intron in complex with both the 5'- and the 3'-exons. This complex corresponds to the splicing intermediate before the exon ligation step. It reveals how the intron uses structurally unprecedented RNA motifs to select the 5'- and 3'-splice sites. The 5'-exon's 3'-OH is positioned for inline nucleophilic attack on the conformationally constrained scissile phosphate at the intron-3'-exon junction. Six phosphates from three disparate RNA strands converge to coordinate two metal ions that are asymmetrically positioned on opposing sides of the reactive phosphate. This structure represents the first splicing complex to include a complete intron, both exons and an organized active site occupied with metal ions. Crystal structure of a self-splicing group I intron with both exons.,Adams PL, Stahley MR, Kosek AB, Wang J, Strobel SA Nature. 2004 Jul 1;430(6995):45-50. Epub 2004 Jun 2. PMID:15175762[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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