FIGURE 6.

Effect of mutations in the LDEVFL or CREEM motif on ATP binding. UV-induced [α-³²P]ATP adduct formation was analyzed in membrane fractions, as described under “Experimental Procedures.” The reaction was performed both in the presence (marked by a plus sign) or absence (marked by minus sign) of 35 μm doxorubicin. A and B, upper gels, autoradiograms showing [α-³²P]ATP binding to wild type DrrAB and various LDEVFL and CREEM mutants. A and B, lower gels, Western blot analysis of the nitrocellulose membranes from the upper gels in A and B, respectively, using anti-DrrA antibodies. C, histogram showing the efficiency of ATP binding to wild type DrrA and mutants. The wild type efficiency was designated as 1. The data presented are averages of three independent experiments. Error bars, S.D.