Identification of a tRNA-like molecule that copurifies with the 7SL RNA of Trypanosoma brucei.
During the purification of Trypanosoma brucei 7SL RNA, we detected a small RNA, 76 nucleotide-long (sRNA-76), that copurified with the 7SL RNP through several different separation steps. In this study, a partial RNA sequence of sRNA-76 was obtained and a complementary oligonucleotide to the RNA sequence was used to clone the corresponding gene. sRNA-76 is very similar to a tRNA molecule and is encoded by a single copy gene. The gene is located next to a tRNA(Val) which has 75.3% homology to T. brucei tRNA(Val) that exists in a different chromosomal locus. The highest homology of sRNA-76 is to mouse and rat tRNA(Asp) (69%), to mouse tRNA(Gly) (68.1%) and to yeast suppressor tRNA(Gly) (69.5%). However, sRNA-76 is neither a tRNA(Asp) nor a tRNA(Gly), since it has a Leu anticodon. In addition, sRNA-76 deviates from the canonical tRNA structure in 3 positions. A potential for base pairing between sRNA-76 and 7SL RNA was found in the 100 nt region of 7SL RNA, which is a highly conserved region in all 7SL RNAs.
Béjà
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Department of Membrane Research and Biophysics, Weizmann Institute of Science, Rehovot, Israel.
Ullu
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Michaeli
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D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D016054:DNA, Protozoan / Q000235:genetics; D017125:Genes, Protozoan; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D016053:RNA, Protozoan / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification*; D012343:RNA, Transfer / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification*; D012366:RNA, Transfer, Val / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D014346:Trypanosoma brucei brucei / Q000235:genetics*
D016054:DNA, Protozoan; D016053:RNA, Protozoan; D012366:RNA, Transfer, Val; D012343:RNA, Transfer