Three point mutations R335S, L336V and V476L, distin-guish the sequence of a cytochrome P450CYP6A2 variant assumed to be responsible for 1,1,1-trichloro-2,2-bis-(4¢-chlorophenyl)ethane (DDT) resistance in theRDDT R strain ofDrosophila melanogaster. To determine the impact of each mutation on the function of CYP6A2, the wild-type enzyme (CYP6A2wt) ofCyp6a2was expressed inEscheri-chia colias well as three variants carrying a single mutation, the double mutant CYP6A2vSV and the triple mutant CYP6A2vSVL. All CYP6A2 variants were less stable than the CYP6A2wt protein. .
