The L2 Loop Peptide of recA Stiffens and restricts Base Motions of Single-stranded DNA Similar to Intact Protein
Journal article, 1999

The L2 loop in the RecA protein is the catalytic center for DNA strand exchange, Here we investigate the DMA binding properties of the L2 loop peptide using optical spectroscopy with polarized light. Both fluorescence intensity and anisotropy of an etheno-modified poly(dA) increase upon peptide binding, indicate that the base motions of single-stranded DNA are restricted in the complex. In agreement with this conclusion, the peptide-poly(dT) complex exhibits a significant linear dichroism signal. The peptide is also found to modify the structure of double-stranded DNA, but does not denature it. It is inferred that strand separation may not be required for the formation of a joint molecule.

DNA binding


homologous recombination

RecA protein

DNA base motion


T. Selmane

Pernilla Wittung Stafshede

Department of Physical Chemistry

F. Maraboeuf

O. Voloshin

Bengt Nordén

Department of Physical Chemistry

D. Camerini-Otero

M. Takahashi

FEBS Letters

0014-5793 (ISSN) 18733468 (eISSN)

Vol. 446 1 30-34

Areas of Advance

Nanoscience and Nanotechnology


Life Science Engineering (2010-2018)

Materials Science

Subject Categories

Physical Chemistry


Basic sciences



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