(a) PLP binding interaction in the PfSHMT homodimer with PLP in yellow, amino-acid residues from one PfSHMT protomer in green and those from the other protomer in pink. Dashed lines indicate hydrogen-bond distances (in Å). Residues Ser100, Ser102, His129, Thr183, Asp208, His211, His236 and Lys237 are from one protomer and Tyr′54 and Gly′272 are from the other protomer. (b) PLP–glycine binding pocket and (c) THF binding pocket with bound 5FTHF from EcSHMT from superimposition of PfSHMT and EcSHMT (PDB entry 1dfo
) to map the substrate binding pockets and residues at the pockets. (d) Primary amino-acid sequence alignment of SHMTs indicates three inserted sequences in PfSHMT and mammalian SHMTs compared with bacterial SHMTs. The PfSHMT residues Cys125 and Cys364 and hSHMT residues Cys204 and Cys389 as well as the human flap motif are indicated.