Meselson-Radding model

Cleavage - one strand is cleaved by an endonuclease. Chain displacement - DNA synthesis displaces a chain. Invasion – The single stranded chain invades a homologous double-stranded DNA molecule. Catalysed by RecA. Chain removal – the displaced chain is digested. Ligation – produces a Holliday junction. Branch migration - increases heteroduplex, catalysed by RuvAB. Isomerization - the strands of the Holliday junction spontaneously cross and uncross, does not require catalysis. Resolution - The crossed strands of the Holliday junction cleaved by RuvC.