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Publication Abstract from PubMed

Group I introns are catalytic RNAs capable of orchestrating two sequential phosphotransesterification reactions that result in self-splicing. To understand how the group I intron active site facilitates catalysis, we have solved the structure of an active ribozyme derived from the orf142-I2 intron from phage Twort bound to a four-nucleotide product RNA at a resolution of 3.6 A. In addition to the three conserved domains characteristic of all group I introns, the Twort ribozyme has peripheral insertions characteristic of phage introns. These elements form a ring that completely envelops the active site, where a snug pocket for guanosine is formed by a series of stacked base triples. The structure of the active site reveals three potential binding sites for catalytic metals, and invokes a role for the 2' hydroxyl of the guanosine substrate in organization of the active site for catalysis.

Crystal structure of a phage Twort group I ribozyme-product complex.,Golden BL, Kim H, Chase E Nat Struct Mol Biol. 2005 Jan;12(1):82-9. Epub 2004 Dec 5. PMID:15580277^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.