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Updated: May 7, 2026

Analysis of RNA Processing Reactions Using Cell Free Systems: 3' End Cleavage of Pre-mRNA Substrates in vitro
Published on: May 3, 2014
Ribosomal precursor 3' end formation requires a conserved element upstream of the promoter
Abstract:
In Xenopus laevis the 3' end of the longest intact ribosomal RNA precursor is formed by a processing event at site T2, which is located 7860 bp downstream of the site of transcription initiation. Processing at T2 is eliminated by mutations within the T2 box, a 7 nucleotide conserved element, GACTTGC, located 15 bp downstream of the 3' ends. The same conserved box is also present at T3, a site 60 bp upstream of the gene promoter and that is part of a termination site. Surprisingly, mutations within the T3 box also eliminate processing at T2. To obtain proper T2 function, T3 can be at any distance but must be in the correct orientation upstream of a ribosomal gene promoter.
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