Multiplexed protein-DNA cross-linking: Scrunching in transcription start site selection

• Autores: Jared T. Winkelman, I. O. Vvedenskaya, Yuanchao Zhang, Yu Zhang
• Localización: Science, ISSN 0036-8075, Vol. 351, Nº 6277, 2016, págs. 1090-1093
• Idioma: inglés
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• Resumen

  • In bacterial transcription initiation, RNA polymerase (RNAP) selects a transcription start site (TSS) at variable distances downstream of core promoter elements. Using next-generation sequencing and unnatural amino acid–mediated protein-DNA cross-linking, we have determined, for a library of 410 promoter sequences, the TSS, the RNAP leading-edge position, and the RNAP trailing-edge position. We find that a promoter element upstream of the TSS, the “discriminator,” participates in TSS selection, and that, as the TSS changes, the RNAP leading-edge position changes, but the RNAP trailing-edge position does not change. Changes in the RNAP leading-edge position, but not the RNAP trailing-edge position, are a defining hallmark of the “DNA scrunching” that occurs concurrent with RNA synthesis in initial transcription. We propose that TSS selection involves DNA scrunching prior to RNA synthesis.