Conformational transition of DNA bound to Hfq probed by infrared spectroscopy

Overview of Geinguenaud F. et al.

AuthorsGeinguenaud F., Calandrini V., Teixeira J., Mayer C., Liquier J., Lavelle C., Arluison V.
AffiliationUFR SMBH, Université Paris 13, Bobigny F-93017, France, Laboratoire Léon Brillouin, Commissariat à l’Energie Atomique, CNRS-UMR 12, Bat 563, 91191 Gif-sur-Yvette, France. Centre de Biophysique Moléculaire, CNRS, Orléans F-45071 & synchrotron Soleil, L’Orme de Merisiers, B.P. 48, 91192 Gif-sur-Yvette, France, Unité de dynamique structurale des macromolécules, Département de Biologie Structurale et Chimie, Institut Pasteur, 25 rue du Dr Roux, 75015 Paris, France, Université Paris Diderot-Paris 7, Paris F-75013, France, URA 2185 CNRS, Paris F-75015, France, Interdisciplinary Research Institute, CNRS-USR 3078, Villeneuve 
d’Ascq F-59655, France, Laboratoire de Microscopie Moléculaire et Cellulaire, CNRS-UMR 8126, Institut de cancérologie Gustave Roussy et Univ. Paris-Sud, Villejuif F-94805, France, Laboratoire Jean Perrin, CNRS-FRE 3132 and Univ. Paris 6, Paris, F-75006, France,  
JournalPhysical Chemistry Chemical Physics
Year 2010

Abstract


Hfq is a bacterial protein involved in RNA metabolism. Besides this, Hfq’s role in DNA restructuring has also been suggested. Since this mechanism remains unclear, we examined the DNA conformation upon Hfq binding by combining vibrational spectroscopy and neutron scattering. Our analysis reveals that Hfq, which preferentially interacts with deoxyadenosine rich sequences, induces partial opening of dA–dT sequences accompanied by sugar repuckering of the dA strand and hence results in a heteronomous A/B duplex. Sugar repuckering is probably correlated with a global dehydration of the complex. By taking into account Hfq’s preferential binding to A-tracts, which are commonly found in promoters, potential biological implications of Hfq binding to DNA are discussed.