Mutations in Plasmodium falciparumCytochrome b That Are Associated with Atovaquone Resistance Are Located at a Putative Drug-Binding Site

(A) Putative P. falciparum CYT bcontact residues involved in atovaquone binding and the residues that were mutated in the atovaquone-resistant parasites. Atovaquone is represented in green stick form, with its lone electron pairs shown in light blue. The electron densities of all the atovaquone atoms are represented by thin lines. All amino acid residues shown as thick or thin sticks in this figure, except for T142, K272, P275, and G280, are predicted contact residues. The thin sticks represent the contact residues, and the thick sticks represent the contact residues that were mutated in the resistant parasite lines. Residues that were mutated inP. falciparum are shown in purple, those in P. yoelii are shown in yellow, and those in P. carinii are shown in orange. The red sticks represent residues that were predicted to be involved in differential atovaquone binding between P. falciparum and chicken CYT b. (B) Putative P. falciparum CYT b contact residues involved in atovaquone binding with the mutated residues from P. falciparum (purple), P. yoelii (yellow), and P. carinii (orange) that are associated with atovaquone resistance. (C) Putative chicken CYT b contact residues involved in atovaquone binding.