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NFI and Oct-1 bend the Ad5 origin in the same direction leading to optimal DNA replication

Monika E Mysiak1, Claire Wyman, P Elly Holthuizen

  • 1Department of Physiological Chemistry, University Medical Centre Utrecht and Centre for Biomedical Genetics, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands.

Nucleic Acids Research
|December 4, 2004
PubMed

Insights

Nuclear Factor I (NFI) and Octamer Binding Protein (Oct-1) enhance DNA replication by bending the Ad5 origin DNA. This collective bending facilitates preinitiation complex assembly and boosts replication synergy.

Area of Science:

  • Molecular Biology
  • Virology
  • Biophysics

Background:

  • Nuclear Factor I (NFI) and Octamer Binding Protein (Oct-1) are cellular transcription factors crucial for viral DNA replication.
  • These factors bind to the Ad5 origin of replication, enhancing initiation.
  • Previous studies showed NFI induces a 60-degree bend in the origin DNA.

Purpose of the Study:

  • To quantify the DNA bending induced by Oct-1.
  • To investigate the collective DNA bending upon simultaneous NFI and Oct-1 binding.
  • To determine the functional role of DNA bending in Ad5 replication enhancement.

Main Methods:

  • Scanning force microscopy to visualize DNA bending.
  • Functional replication assays to assess replication efficiency.

Main Results:

  • Oct-1 induces a 42-degree bend in the Ad5 origin DNA.
  • Simultaneous binding of NFI and Oct-1 results in an 82-degree collective bend, with bends oriented towards each other.
  • This extensive DNA bending synergistically enhances DNA replication.

Conclusions:

  • Collective DNA bending by NFI and Oct-1 is a key mechanism for enhancing Ad5 replication.
  • The induced DNA bending likely facilitates optimal preinitiation complex assembly.
  • NFI and Oct-1 play a significant stimulatory role in viral DNA replication through DNA bending.

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