In trypanosomatids, the RNA polymerase I （RNAPI）-dependent promoters controlling the ribosomal RNA （rRNA） genes have been well identified. Although the RNAPI transcription machinery recognizes the DNA conformation...In trypanosomatids, the RNA polymerase I （RNAPI）-dependent promoters controlling the ribosomal RNA （rRNA） genes have been well identified. Although the RNAPI transcription machinery recognizes the DNA conformation instead of the DNA sequence of promoters, no con- formational study has been reported for these promoters. Here we present the in silico analysis of the intrinsic DNA curvature of the rRNA gene core promoters in Trypanosoma brucei, Trypanosoma cruzi, and Leiskmania major. We found that, in spite of the absence of sequence conservation, these promoters hold conformational properties similar to other eukaryotic rRNA promoters. Our results also indicated that the intrinsic DNA curvature pattern is conserved within the Leishmania genus and also among strains of T. cruzi and T. brucei. Furthermore, we analyzed the impact of point mutations on the intrinsic curvature and their impact on the promoter activity. Furthermore, we found that the core promoters of protein-coding genes transcribed by RNAPI in T. brucei show the same conserved conformational characteristics. Overall, our results indicate that DNA intrinsic curvature of the rRNA gene core promoters is conserved in these ancient eukaryotes and such con- served curvature might be a requirement of RNAPI machinery for transcription of not only rRNA genes but also protein-coding genes.展开更多
基金financially supported by the Programa de Desarrollo de las Ciencias Bsicas (PEDECIBA) Uruguaythe Comision Sectorial de Investigación Científica (CSIC) de la Universidad de la República (Udela R) Uruguay (Grant No. CSIC-C635 348)the Agencia Nacional de Investigación e Innovación (ANII) Uruguay
文摘In trypanosomatids, the RNA polymerase I （RNAPI）-dependent promoters controlling the ribosomal RNA （rRNA） genes have been well identified. Although the RNAPI transcription machinery recognizes the DNA conformation instead of the DNA sequence of promoters, no con- formational study has been reported for these promoters. Here we present the in silico analysis of the intrinsic DNA curvature of the rRNA gene core promoters in Trypanosoma brucei, Trypanosoma cruzi, and Leiskmania major. We found that, in spite of the absence of sequence conservation, these promoters hold conformational properties similar to other eukaryotic rRNA promoters. Our results also indicated that the intrinsic DNA curvature pattern is conserved within the Leishmania genus and also among strains of T. cruzi and T. brucei. Furthermore, we analyzed the impact of point mutations on the intrinsic curvature and their impact on the promoter activity. Furthermore, we found that the core promoters of protein-coding genes transcribed by RNAPI in T. brucei show the same conserved conformational characteristics. Overall, our results indicate that DNA intrinsic curvature of the rRNA gene core promoters is conserved in these ancient eukaryotes and such con- served curvature might be a requirement of RNAPI machinery for transcription of not only rRNA genes but also protein-coding genes.
