Guide RNAs and guide RNA genes in the cryptobiid kinetoplastid protozoan, Trypanoplasma borreli.
Trypanoplasma borreli belongs to the bodonid/cryptobiid group of kinetoplastid protozoa, which represents a sister group to the trypanosomatids. RNA transcripts from several mitochondrial genes in this organism undergo the trypanosomatid type of uridine addition/deletion RNA editing. A guide RNA (gRNA) cDNA library was constructed and five gRNAs were identified, one for editing the ribosomal protein S12 mRNA, three for editing the cytochrome oxidase subunit I mRNA, and one for editing the cytochrome b mRNA. All of the gRNAs contained nonencoded oligo[U] sequences at the 3' end, as is common with gRNAs in trypanosomatids, but also contained nonencoded oligo[U] sequences at the 5' end. The mechanism for addition of the 5' nonencoded oligo[U] sequence and the function of this sequence are unknown. The T. borreli gRNAs were shorter (25-35 nt, excluding the 5' oligo[U]) than gRNAs in trypanosomatids (45-50 nt), indicating a smaller size of editing blocks in this organism. Genomic sequences for two gRNAs were cloned and sequenced. These two gRNA-encoding sequences were shown to originate from the 180-kb Component I molecules, which represent a possible homologue of minicircle DNA in trypanosomatids, and not from the 80-kb Component II molecules, which contain the structural genes and cryptogenes.
Howard Hughes Medical Institute, University of California, Los Angeles 90095-1662, USA.
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Yasuhira
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Simpson
D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004272:DNA, Mitochondrial / Q000235:genetics; D016054:DNA, Protozoan / Q000235:genetics; D015723:Gene Library; D017125:Genes, Protozoan; D016830:Kinetoplastida / Q000235:genetics*; D008969:Molecular Sequence Data; D017394:RNA, Guide, Kinetoplastida / Q000235:genetics*; D016053:RNA, Protozoan / Q000235:genetics*
D004272:DNA, Mitochondrial; D016054:DNA, Protozoan; D016053:RNA, Protozoan; D017394:RNA, Guide, Kinetoplastida