The gene coding for myristoyl-CoA:protein N-myristoyltransferase (NMT) has been cloned from the malaria parasite Plasmodium falciparum. The gene appears to be single copy and mRNA is expressed in asexual blood-stage forms. Comparison of cDNA and genomic sequences identified three small introns. The open reading frame codes for a 410-amino-acid protein and no evidence of forms with an extended N-terminal coding sequence was obtained. Residues important in substrate binding and in the catalytic mechanism in other species are conserved. The protein was expressed from a plasmid in Escherichia coli, partially purified and shown to have enzymic activity using a synthetic peptide substrate. Comparison of the malaria parasite protein with that derived from the human gene showed a different pattern of inhibition by chemical modification. Human NMT activity was inhibited by diethylpyrocarbonate and partially inhibited by iodacetamide, whereas P. falciparum NMT activity was not inhibited by either pre-treatment. Since the enzyme in infectious fungi is a target for potential chemotherapeutic drugs, it should also be investigated in the context of parasitic infections such as that responsible for malaria.
- Acyltransferases, Amino Acid Sequence, Animals, Candida albicans, Cloning, Molecular, Diethyl Pyrocarbonate, Ethylmaleimide, Humans, Kinetics, Molecular Sequence Data, Open Reading Frames, Plasmodium falciparum, Polymerase Chain Reaction, Protein Biosynthesis, Recombinant Proteins, Saccharomyces cerevisiae, Sequence Alignment, Sequence Homology, Amino Acid