Quantifying how DNA stretches, melts and changes twist under tension

TY - JOUR

T1 - Quantifying how DNA stretches, melts and changes twist under tension

AU - Gross, Peter

AU - Laurens, Niels

AU - Oddershede, Lene Broeng

AU - Bockelmann, Ulrich

AU - Peterman, Erwin J. G.

AU - Wuite, Gijs J.L.

PY - 2011/9/1

Y1 - 2011/9/1

N2 - In cells, DNA is constantly twisted, bent and stretched by numerous proteins mediating genome transactions. Understanding these essential biological processes requires in-depth knowledge of how DNA complies to mechanical stress. Two important physical features of DNA, helical structure and sequence, are not incorporated in current descriptions of DNA elasticity. Here we connect well-defined force-extension measurements with a new model for DNA elasticity: the twistable worm-like chain, in which DNA is considered a helical, elastic entity that complies to tension by extending and twisting. In addition, we reveal hitherto unnoticed stick-slip dynamics during DNA overstretching at 65pN, caused by the loss of base-pairing interactions. An equilibrium thermodynamic model solely based on DNA sequence and elasticity is presented, which captures the full complexity of this transition. These results offer deep quantitative insight in the physical properties of DNA and present a new standard description of DNA mechanics.

AB - In cells, DNA is constantly twisted, bent and stretched by numerous proteins mediating genome transactions. Understanding these essential biological processes requires in-depth knowledge of how DNA complies to mechanical stress. Two important physical features of DNA, helical structure and sequence, are not incorporated in current descriptions of DNA elasticity. Here we connect well-defined force-extension measurements with a new model for DNA elasticity: the twistable worm-like chain, in which DNA is considered a helical, elastic entity that complies to tension by extending and twisting. In addition, we reveal hitherto unnoticed stick-slip dynamics during DNA overstretching at 65pN, caused by the loss of base-pairing interactions. An equilibrium thermodynamic model solely based on DNA sequence and elasticity is presented, which captures the full complexity of this transition. These results offer deep quantitative insight in the physical properties of DNA and present a new standard description of DNA mechanics.

U2 - 10.1038/nphys2002

DO - 10.1038/nphys2002

M3 - Journal article

SN - 1745-2473

VL - 7

SP - 731

EP - 736

JO - Nature Physics

JF - Nature Physics

IS - 9

ER -