5j02

Structure of the lariat form of a chimeric derivative of the Oceanobacillus iheyensis group II intron in the presence of NH4+, MG2+ and an inactive 5' exon.

spinqualitylabelsall models 5j02, resolution 3.49Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5j02 is a 2 chain structure with sequence from Oceanobacillus iheyensis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 3.493Å Ligands: 6F7, MG, NH4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed The 2'-5' branch of nuclear premessenger introns is believed to have been inherited from self-splicing group II introns, which are retrotransposons of bacterial origin. Our crystal structures at 3.4 and 3.5 angstrom of an excised group II intron in branched ("lariat") form show that the 2'-5' branch organizes a network of active-site tertiary interactions that position the intron terminal 3'-hydroxyl group into a configuration poised to initiate reverse splicing, the first step in retrotransposition. Moreover, the branchpoint and flanking helices must undergo a base-pairing switch after branch formation. A group II-based model of the active site of the nuclear splicing machinery (the spliceosome) is proposed. The crucial role of the lariat conformation in active-site assembly and catalysis explains its prevalence in modern splicing. Crystal structures of a group II intron lariat primed for reverse splicing.,Costa M, Walbott H, Monachello D, Westhof E, Michel F Science. 2016 Dec 2;354(6316). pii: aaf9258. PMID:27934709 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Ribozyme 3D structures

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