Fosado Yair A G, Howard Jamieson, Weir Simon, Noy Agnes, Leake Mark C, Michieletto Davide
School of Physics and Astronomy, University of Edinburgh, Peter Guthrie Tait Road, Edinburgh EH9 3FD, United Kingdom.
School of Physics, Engineering and Technology, University of York, York, YO10 5DD, United Kingdom.
Phys Rev Lett. 2023 Feb 3;130(5):058203. doi: 10.1103/PhysRevLett.130.058203.
In spite of the nanoscale and single-molecule insights into nucleoid associated proteins (NAPs), their role in modulating the mesoscale viscoelasticity of entangled DNA has been overlooked so far. By combining microrheology and molecular dynamics simulation, we find that the abundant NAP "integration host factor" (IHF) lowers the viscosity of entangled λDNA 20-fold at physiological concentrations and stoichiometries. Our results suggest that IHF may play a previously unappreciated role in resolving DNA entanglements and in turn may be acting as a "genomic fluidizer" for bacterial genomes.
尽管对类核相关蛋白（NAPs）有了纳米尺度和单分子层面的认识，但它们在调节纠缠DNA的中尺度粘弹性方面的作用迄今仍被忽视。通过结合微观流变学和分子动力学模拟，我们发现丰富的NAP“整合宿主因子”（IHF）在生理浓度和化学计量比下可将纠缠的λDNA的粘度降低20倍。我们的结果表明，IHF可能在解决DNA缠结方面发挥了先前未被认识到的作用，进而可能作为细菌基因组的“基因组流化剂”。
