title: Nuclear rRNA transcript processing versus internal transcribed spacer secondary structure.
abstract: rRNA is one of the few universal features of life, making it uniquely suited to assess phylogenetic relationships. The processing of the initial polycistronic rRNA transcript is also a conserved process, involving numerous cleavage events and the generation of secondary structures. The secondary structure of the internal transcribed spacer (ITS) regions of nuclear rRNA transcripts are well known for a wide variety of eukaryotes and have been used to aid in the alignment of these sequences for phylogenetic comparisons. By contrast, study of the processing of the initial rRNA transcripts has been largely limited to yeast, mice, rats, and humans. Here I examine the known cleavage sites in the two ITS regions and their positions relative to the secondary structure. A better understanding of the conservation of secondary structures and cleavage sites within the ITS regions will improve evolutionary inferences based on these sequences.
authors: Division of Biology and Medicine, Brown University, Providence, RI 02912, USA. Electronic address: Annette_Coleman@Brown.edu.
authors: Annette W
authors: AW
authors: Coleman
mesh_terms: D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D021903:DNA, Ribosomal Spacer / Q000737:chemistry; D015870:Gene Expression; D006801:Humans; D051379:Mice; D009690:Nucleic Acid Conformation; D010802:Phylogeny; D010944:Plants; D012322:RNA Precursors / Q000235:genetics / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D012335:RNA, Ribosomal / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D015003:Yeasts / Q000235:genetics / Q000378:metabolism
chemical_list: D021903:DNA, Ribosomal Spacer; D012322:RNA Precursors; D012335:RNA, Ribosomal
keywords: RNA secondary structure; internal transcribed spacer; nuclear ribosome synthesis; rRNA processing