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Designed architectural proteins that tune DNA looping in bacteria

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  • معلومة اضافية
    • بيانات النشر:
      Oxford University Press, 2021.
    • الموضوع:
      2021
    • نبذة مختصرة :
      Architectural proteins alter the shape of DNA. Some distort the double helix by introducing sharp kinks. This can serve to relieve strain in tightly-bent DNA structures. Here, we design and test artificial architectural proteins based on a sequence-specific Transcription Activator-like Effector (TALE) protein, either alone or fused to a eukaryotic high mobility group B (HMGB) DNA-bending domain. We hypothesized that TALE protein binding would stiffen DNA to bending and twisting, acting as an architectural protein that antagonizes the formation of small DNA loops. In contrast, fusion to an HMGB domain was hypothesized to generate a targeted DNA-bending architectural protein that facilitates DNA looping. We provide evidence from Escherichia coli Lac repressor gene regulatory loops supporting these hypotheses in living bacteria. Both data fitting to a thermodynamic DNA looping model and sophisticated molecular modeling support the interpretation of these results. We find that TALE protein binding inhibits looping by stiffening DNA to bending and twisting, while the Nhp6A domain enhances looping by bending DNA without introducing twisting flexibility. Our work illustrates artificial approaches to sculpt DNA geometry with functional consequences. Similar approaches may be applicable to tune the stability of small DNA loops in eukaryotes.
      Graphical Abstract Graphical AbstractThe stability of Lac repressor loops in E. coli is tuned by designed artificial sequence-specific architectural DNA binding proteins that stiffen or kink looped DNA, impacting gene expression in opposite ways.
    • ISSN:
      1362-4962
      0305-1048
    • Rights:
      OPEN
    • الرقم المعرف:
      edsair.doi.dedup.....7a4f94e27d8ca62719d6d5daa3ec620d