Suppression of DNA damage sensitivity occurs upstream of Rad51. Cell survival frequencies on 0.002% MMS-containing plates versus control plates for wild-type cells (JY741), rad50-d (KT002), rhp51-d (KT00c), rhp51-d pku70-d (KT10c5), pku80-d (KT090), rad50-d pku80-d (KT192), lig4-d (KT1a0), and rad50-d lig4-d cells (KT1a2). Standard deviations are shown by error bars (for two to four independent experiments).