The molecular model of Pf-DHFR. The Pf-DHFR model (green) with the aa64-100 loop highlighted (red). The N-terminal part of the Pf-DHFR (white) was not included in the Pf-DHFR model and it is here shown together with the Leishmania major-TS structure (white and cyan, respectively) to illustrative that the aa64-100 loop does not interfere with these parts of the DHFR-TS complex. The Pf-DHFR substrate and cofactor are just visible at the lower right part of Pf-DHFR (orange). The surfaces are solvent-accessible surfaces generated with SYBYL.