We focus mainly on the regulation of DNA motor proteins. These proteins move along the DNA duplex and remove molecules that form obstacles to sensing DNA damage and repairing it through homologous recombination (HR). We have found that modification of these motor proteins through phosphorylation is required for regulating their action and limiting the occurrence of HR to the right situation. Too much HR, or too little, can destabilize the genome. Therefore, regulation of these key proteins is essential for maintaining both the right balance of HR and genome stability.