Journal
JOURNAL OF MOLECULAR BIOLOGY
Volume 367, Issue 2, Pages 501-513Publisher
ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD
DOI: 10.1016/j.jmb.2007.01.005
Keywords
ferredoxin-NADP(+) reductase; Plasmodium falciparum; apicoplast; protein structure; disulfide-stabilized dimer
Categories
Ask authors/readers for more resources
The completion of the Plasmodium falciparum genome sequence has recently promoted the search for new antimalarial drugs. More specifically, metabolic pathways of the apicoplast, a key organelle for survival of the parasite, have been recognized as potential targets for the development of specific new antimalarial agents. As most apicomplexan parasites, R falciparum displays a plant-type ferredoxin-NADP(+) reductase, yielding reduced ferredoxin for essential biosynthetic pathways in the apicoplast. Here we report a molecular, kinetic and ligand binding characterization of the recombinant ferredoxin-NADP(+) reductase from R falciparum, in the light of current data available for plant ferredoxin-NADP(+) reductases. In parallel with the functional characterization, we describe the crystal structures of R falciparum ferredoxin-NADP(+) reductase in free form and in complex with 2-phospho-AMP (at 2.4 and 2.7 angstrom resolution, respectively). The enzyme displays structural properties likely to be unique to plasmodial reductases. In particular, the two crystal structures highlight a covalent dimer, which relies on the oxidation of residue Cys99 in two opposing subunits, and a helix-coil transition that occurs in the NADP-binding domain, triggered by 2'-phospho-AMP binding. Studies in solution show that NADP(+), as well as 2'-phospho-AMP, promotes the formation of the disulfide-stabilized dimer. The isolated dimer is essentially inactive, but full activity is recovered upon disulfide reduction. The occurrence of residues unique to the plasmodial enzyme, and the discovery of specific conformational properties, highlight the NADP-binding domain of R falciparum ferredoxin-NADP(+) reductase as particularly suited for the rational development of antimalarial compounds. (c) 2007 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available