Cleavage of non-tRNA substrates by eukaryal tRNA splicing endonucleases.
Eukaryal tRNA splicing endonucleases use the mature domains of pre-tRNAs as their primary recognition elements. However, they can also cleave in a mode that is independent of the mature domain, when substrates are able to form the bulge-helix-bulge structure (BHB), which is cleaved by archaeal tRNA endonucleases. We present evidence that the eukaryal enzymes cleave their substrates after forming a structure that resembles the BHB. Consequently, these enzymes can cleave substrates that lack the mature domain altogether. That raises the possibility that these enzymes could also cleave non-tRNA substrates that already have a BHB. As predicted, they can do so, both in vitro and in vivo.
Fruscoloni
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Istituto di Biologia Cellulare, CNR, Campus 'A. Buzzati-Traverso', Via E. Ramarini, 32, 00016 Monterotondo Scalo (RM), Italy.
Baldi
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Tocchini-Valentini
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D000818:Animals; D001665:Binding Sites; D004722:Endoribonucleases / Q000378:metabolism*; D066298:In Vitro Techniques; D009690:Nucleic Acid Conformation; D012322:RNA Precursors / Q000737:chemistry / Q000378:metabolism; D012326:RNA Splicing; D019642:RNA, Archaeal / Q000737:chemistry / Q000378:metabolism; D013379:Substrate Specificity; D014981:Xenopus
D012322:RNA Precursors; D019642:RNA, Archaeal; D004722:Endoribonucleases; C051012:splicing endonuclease