Structure of the (E)‐4‐hydroxy‐3‐methyl‐but‐2‐enyl‐diphosphate reductase from Plasmodium falciparum

Abstract

a b s t r a c tTerpenoid precursor biosynthesis occurs in human and many pathogenic organisms via the mevalonate and 2-C-methyl-D-erythritol-4-phosphate (MEP) pathways, respectively. We determined the X-ray structure of the Fe/S containing (E)-4-hydroxy-3-methyl-but-2-enyl-diphosphate reductase (LytB) of the pathogenic protozoa Plasmodium falciparum which catalyzes the terminal step of the MEP pathway. The cloverleaf fold and the active site of P. falciparum LytB corresponds to those of the Aquifex aeolicus and Escherichia coli enzymes. Its distinct electron donor [2Fe-2S] ferredoxin was modeled to its binding site by docking calculations. The presented structural data provide a platform for a rational search of anti-malarian drugs.

Bioenergetics of Monoterpenoid Essential Oil Biosynthesis in Nonphotosynthetic Glandular Trichomes

“…The authors concluded that Fd was most likely to attach to a shallow well formed by the N terminus, helix a1B, and the loops near strands b4A and b4B. Our FNR-Fd-HDR docking simulations indicated that one of the lowest energy ternary complexes had a molecular surface that was very similar to that suggested previously (Rekittke et al, 2013). Interestingly, six residues purportedly involved in the Fd-HDR interaction differed between the major and minor Fd isoforms of peppermint GTs (Glu-54, Lys-55, Thr-57, Lys-69, Glu-73, and Ala-85 in the major isoform corresponded to Val-54, Ser-55, Ser-57, Asn-69, Gln-73, and Ser-85 in the minor isoform, respectively; Fig.…”

“…4). The electron transfer reactions of reductive steps of the MEP pathway, catalyzed by 1-hydroxy-2-methyl-2-(E)-butenyl-4-diphosphate synthase (HDS) and 1-hydroxy-2-methyl-2-(E)-butenyl-4-diphosphate reductase (HDR), employ Fd and FNR (Seemann et al, 2006;Rekittke et al, 2013). This cofactor requirement is in accordance with our modeling prediction that Fd recycling is essential for monoterpene biosynthesis (Table I).…”

“…This is a logical consequence of the fact that Fd is a cofactor for electron transfer reactions toward two reductive enzymes of the MEP pathway (Seemann et al, 2006;Rekittke et al, 2013) and flavone hydroxylases (Berim et al, 2014), which are involved in the formation of the major products of mint GTs (monoterpenes and methoxylated flavones, respectively). In earlier versions of menpiGT_2015, Fd served as a substrate for FNR, which is the direction of electron flow in photosynthetic cells.…”

“…Rekittke et al (2013) employed docking calculations to select the energetically most favorable complexes between HDR and the cognate Fd from Plasmodium falciparum. The authors concluded that Fd was most likely to attach to a shallow well formed by the N terminus, helix a1B, and the loops near strands b4A and b4B.…”

“…The structures of the peppermint Fd and FNR isoforms obtained by this approach (excluding iron-sulfur clusters and ligands) were energy minimized in Chimera, and the iron-sulfur clusters and ligands were subsequently reintroduced by docking. The same method was employed to produce a peppermint HDR structure (following alignment to the published Plasmodium falciparum HDR structure; Rekittke et al, 2013). The structure files for peppermint Fd, FNR, and HDR were submitted to the GRAMM-X server (Tovchigrechko and Vasker, 2006) to assess interactions in a three-protein complex (Fd-FNR as receptor and HDR as ligand).…”