title: Fine structure of ribosomal RNA. IV. Extraordinary evolutionary conservation in sequences that flank introns in rDNA.
abstract: By hybridization and DNA sequencing, we have defined a specific region in Xenopus rDNA that is extremely conserved between Tetrahymena, a protozoan, and Xenopus, a vertebrate. This highly conserved region is found at the site where an intron has been shown to interrupt Tetrahymena rDNA [1,2], although we have not detected introns in genomic or cloned Xenopus rDNA. We have noted that the sequences corresponding to nuclear rDNA interon-flanking regions show an intriguing complementarity to tRNAiMet. This suggests possible models for tRNA-rRNA interactions in protein synthesis and/or rRNA splicing.
mesh_terms: D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D003001:Cloning, Molecular; D004247:DNA; D004262:DNA Restriction Enzymes; D004274:DNA, Recombinant; D009690:Nucleic Acid Conformation; D009693:Nucleic Acid Hybridization; D009838:Oligodeoxyribonucleotides / Q000032:analysis; D012335:RNA, Ribosomal; D013769:Tetrahymena pyriformis / Q000032:analysis; D014981:Xenopus
chemical_list: D004274:DNA, Recombinant; D009838:Oligodeoxyribonucleotides; D012335:RNA, Ribosomal; D004247:DNA; D004262:DNA Restriction Enzymes