Plasmodium falciparum: isolation and characterisation of a gene encoding protozoan GMP synthase

The final step in guanylate nucleotide biosynthesis is catalysed by GMP synthase. This paper presents the first isolation of a gene encoding a protozoan GMP synthase. The deduced amino acid sequence from Plasmodium falciparum shares 40% identity with yeast GMP synthase and contains motifs conserved in catalysis. Expression of the gene is regulated through the parasite's development in human red blood cells with maximal expression during the point of DNA replication. Psicofuranine, which inhibits GMP synthase, interrupts parasite growth, supporting the role of this enzyme. These findings will aid development of inhibitors of purine salvage in malaria parasites.