Folding transition of large DNA completely inhibits the action of a restriction endonuclease as revealed by single‐chain observation

FEBS Letters

Oana, Hidehiro¹  Yoshikawa, Yuko³  Tsumoto, Kanta²  Yoshikawa, Kenichi¹ 

[1] Department of Physics, Kyoto University & CREST, Kyoto 606-8502, Japan;Graduate School of Human Informatics, Nagoya University, Nagoya 464-8601, Japan;Department of Food and Nutrition, Nagoya Bunri College, Nagoya 451-0077, Japan

关键词: DNA;    Spermine;    Restriction enzyme;    Fluorescence microscopy;   

DOI  :  10.1016/S0014-5793(02)03448-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The biochemical characteristics of lambda DNA chains in folded/unfolded states upon cleavage by the restriction enzyme ApaLI were investigated in the presence of spermine. These characteristics of DNA chains depending on their higher-order structure were studied at the single-molecule level using fluorescence microscopy. With a low concentration of spermine, lambda DNA takes a random coiled conformation and allows digestion by the enzyme, while under a high concentration of spermine, lambda DNA takes a compact folded structure and inhibits such attack. Together with comparative experiments on short oligomeric DNA, our results suggest that the transition in the higher-order structure causes on/off-type switching of sensitivity to the enzyme.

【 授权许可】

Unknown