1x8w
From Proteopedia
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Structure of the Tetrahymena Ribozyme: Base Triple Sandwich and Metal Ion at the Active Site
Overview
The Tetrahymena intron is an RNA catalyst, or ribozyme. As part of its, self-splicing reaction, this ribozyme catalyzes phosphoryl transfer, between guanosine and a substrate RNA strand. Here we report the refined, crystal structure of an active Tetrahymena ribozyme in the absence of its, RNA substrate at 3.8 A resolution. The 3'-terminal guanosine (omegaG), which serves as the attacking group for RNA cleavage, forms a coplanar, base triple with the G264-C311 base pair, and this base triple is, sandwiched by three other base triples. In addition, a metal ion is, present in the active site, contacting or positioned close to the ribose, of the omegaG and five phosphates. All of these phosphates have been shown, to be important for catalysis. Therefore, we provide a picture of how the, ribozyme active site positions both a catalytic metal ion and the, nucleophilic guanosine for catalysis prior to binding its RNA substrate.
About this Structure
1X8W is a Protein complex structure of sequences from [1] with MG as ligand. Full crystallographic information is available from OCA.
Reference
Structure of the Tetrahymena ribozyme: base triple sandwich and metal ion at the active site., Guo F, Gooding AR, Cech TR, Mol Cell. 2004 Nov 5;16(3):351-62. PMID:15525509
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