title: A model for the involvement of the small nucleolar RNA (U3) in processing eukaryotic ribosomal RNA.
abstract: The nucleotide sequence of chick pre-rRNA between 5.8S and 28S rRNAs is 85% G + C and has the potential to form many different secondary structures. A model is presented in which a small nucleolar RNA, U3, and its associated proteins act as an RNA isomerase to position the pre-rRNA for processing. Cleavage could be performed either by a nuclease present in the U3RNP or by a ribonuclease directed to the proper form of the pre-rRNA.
mesh_terms: D000818:Animals; D001483:Base Sequence; D002466:Cell Nucleolus / Q000502:physiology*; D002645:Chickens; D006860:Hydrogen Bonding; D008954:Models, Biological; D009690:Nucleic Acid Conformation; D009694:Nucleic Acid Precursors / Q000235:genetics*; D012313:RNA / Q000502:physiology*; D012323:RNA Processing, Post-Transcriptional; D012335:RNA, Ribosomal / Q000235:genetics*; D012342:RNA, Small Nuclear
chemical_list: D009694:Nucleic Acid Precursors; D012335:RNA, Ribosomal; D012342:RNA, Small Nuclear; D012313:RNA