Site-directed spin labeling measurements of nanometer distances in nucleic acids using a sequence-independent nitroxide probe.

ABSTRACT: In site-directed spin labeling (SDSL), local structural and dynamic information is obtained via electron paramagnetic resonance (EPR) spectroscopy of a stable nitroxide radical attached site-specifically to a macromolecule. Analysis of electron spin dipolar interactions between pairs of nitroxides yields the inter-nitroxide distance, which provides quantitative structural information. The development of pulse EPR methods has enabled such distance measurements up to 70 A in bio-molecules, thus opening up the possibility of SDSL global structural mapping. This study evaluates SDSL distance measurement using a nitroxide (designated as R5) that can be attached, in an efficient and cost-effective manner, to a phosphorothioate backbone position at arbitrary DNA or RNA sequences. R5 pairs were at

SUBMITTER: Cai Q 

PROVIDER: S-EPMC1635252 | biostudies-literature | 2006

REPOSITORIES: biostudies-literature