DNA helix destabilization by proline and betaine: possible role in the salinity tolerance process

FEBS Letters

Reddy, Arjula R¹  Suryanarayana, Tangirala¹  Rajendrakumar, Chadalavada S.V¹ 

[1] School of Life Sciences, University of Hyderabad, Hyderabad-500 046, India

关键词: Proline;    Betaine;    DNA helix;    T m curves;    Salinity stress;   

DOI  :  10.1016/S0014-5793(97)00588-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Evidence is provided for the ability of proline, a salinity induced osmoprotectant, to destabilize the double helix and lower the T _m of DNA in a concentration dependent manner. At the reported salinity-adaptive bio-accumulation of 1 M and above, proline could considerably decrease the T _m and partially counteract the effect of sodium chloride and spermidine on DNA stability. On the contrary, several other amino acids tested did not show any such destabilizing effect on DNA helix. Enhanced susceptibility to S1 nuclease and insensitivity to DNase I in presence of increasing proline concentrations have further suggested a clear destabilization of the double helix. Such an effect is somewhat reminiscent of the interaction between betaine, another salinity induced osmolyte, and DNA resulting in decreased T _m values. These interactions may be significant in view of the abundance of such osmolytes in cells under salinity stress-adapted conditions, with many a bacterial mutant accumulating them exhibiting improved tolerance to salinity.

【 授权许可】

Unknown