Genetic complementation of Plasmodium falciparum GCH1 in bacteria. (A) Mutation effect on P. falciparum gch1 complementation. Wild-type P. falciparum GCH1 can rescue the loss of a bacterial strain without its own gch1 (folE in bacteria). The loss of functional P. falciparum GCH1 as in the H279S mutant abolishes the complementation activity. Naturally-occurring mutations (N88Y and R230K) were also tested for their genetic complementation activities. (B) Effect of the N-terminal truncation on genetic complementation. A series of the N-terminal truncates was made in order to test their effect on genetic complementation. (C) Effect of the C-terminal helix deletion on genetic complementation. The well-conserved C-terminal helix was removed and tested for the complementation activity by the mutant.