Plasmodium falciparum cytochrome b (PfCYTB)

Plasmodium falciparum cytochrome b (PfCYTB) is an integral membrane protein located in the mitochondrial inner membrane of the malaria parasite. It serves as a core catalytic subunit of the cytochrome bc1 complex (complex III), which is responsible for electron transfer from ubiquinol to cytochrome c as part of mitochondrial oxidative phosphorylation, generating the proton motive force needed for ATP synthesis[1][7]. It is an essential enzyme for parasite survival and a validated antimalarial drug target: inhibitors like atovaquone and several experimental quinolones exert their effect by blocking this protein’s function, leading to parasite death[3][4][5][7]. Drug resistance typically arises through single nucleotide polymorphisms in the cytochrome b gene, especially within the ubiquinol-binding pocket, making monitoring of these mutations important for treatment efficacy and development of new therapies[3][4][5][6][7].

Other names

cytochrome bCYTB

Inhibition of mitochondrial electron transport chain at the cytochrome bc1 complex, causing collapse of the proton gradient and cellular ATP depletion[3][4][5][6][7].