Evidence for hydrophobic catalysis of DNA strand exchangeElectronic supplementary information (ESI) available: Experimental details and DNA sequences, strand exchange yields in the presence of Ficoll and dextran, melting curves and CD spectra in the presence of DME/PEG. See DOI: 10.1039/c5cc01515d

The catalytic role of hydrophobic co-solutes in DNA strand exchange is demonstrated by FRET kinetics. Two mechanisms that contribute to this are base stacking destabilisation and nucleation-promoted DNA strand invasion. We propose that hydrophobic catalysis is involved in the strand-exchange activity of recombination enzymes. DNA strand exchange is catalysed by a hydrophobic environment which destabilises base stacking and promotes DNA breathing.