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Substrate Generation for Endonucleases of CRISPR/Cas Systems
Published on: September 8, 2012
Structure, function, and evolution of the tRNA endonucleases of Archaea: an example of subfunctionalization
Giuseppe D Tocchini-Valentini1, Paolo Fruscoloni, Glauco P Tocchini-Valentini
1Istituto di Biologia Cellulare, Consiglio Nazionale delle Ricerche, Campus A. Buzzati-Traverso, Via Ramarini 32, I-00016 Monterotondo Scalo, Rome, Italy. g.tocchini@ibc.cnr.it
Abstract:
We have detected two paralogs of the tRNA endonuclease gene of Methanocaldococcus jannaschii in the genome of the crenarchaeote Sulfolobus solfataricus. This finding has led to the discovery of a previously unrecognized oligomeric form of the enzyme. The two genes code for two different subunits, both of which are required for cleavage of the pre-tRNA substrate. Thus, there are now three forms of tRNA endonuclease in the Archaea: a homotetramer in some Euryarchaea, a homodimer in other Euryarchaea, and a heterotetramer in the Crenarchaea and the Nanoarchaea. The last-named enzyme, arising most likely by gene duplication and subsequent "subfunctionalization," requires the products of both genes to be active.
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