Effects of sbcB15 and ΔsbcB mutations on survival after UV and γ irradiation in a ΔrecBCD background. The strains used were AB1157 (rec+ sbc+), LMM1724 (ΔrecBCD), LMM1725 (ΔrecBCD ΔsbcB), LMM1726 (ΔrecBCD sbcB15), LMM1732 (ΔrecBCD ΔsbcB sbcC), and LMM1733 (ΔrecBCD sbcB15 sbcC). The values are averages of results from at least three independent experiments.