Characterization of a candidate Trypanosoma brucei U1 small nuclear RNA gene

摘要: We have previously shown that the poly(A) polymerase (PAP) gene of Trypanosoma brucei is interrupted by an intervening sequence. It was postulated removing this intron cis-splicing requires a yet unidentified U1 small nuclear RNA (snRNA), which in other organisms engages base-pair interactions across 5% splice site during early spliceosome assembly. Here we present characterization 75 nucleotide long candidate T. snRNA. Immunoprecipitation studies indicate trimethylguanosine cap structure at end and bound to core proteins common spliceosomal ribonucleoprotein particles. The snRNA has potential for extensive intermolecular base pairing with PAP site. used block replacement mutagenesis identify sequences necessary vivo expression found least two cis-acting elements, tRNA-like A B boxes, located 5%-flanking region are synthesis; no internal close transcription start essential, suggesting promoter architecture distinct from trypanosome U-snRNA genes. © 2001 Elsevier Science B.V. All rights reserved.