Characterization of N-myristoyltransferase from Plasmodium falciparum.
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.
Gunaratne
R S
RS
Division of Parasitology, The National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, U.K. rsg25@mole.bio.cam.ac.uk
Sajid
M
M
Ling
I T
IT
Tripathi
R
R
Pachebat
J A
JA
Holder
A A
AA
D000217:Acyltransferases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D002176:Candida albicans / Q000201:enzymology; D003001:Cloning, Molecular; D004047:Diethyl Pyrocarbonate / Q000494:pharmacology; D005033:Ethylmaleimide / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010963:Plasmodium falciparum / Q000201:enzymology*; D016133:Polymerase Chain Reaction; D014176:Protein Biosynthesis; D011994:Recombinant Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D011994:Recombinant Proteins; D000217:Acyltransferases; C050480:glycylpeptide N-tetradecanoyltransferase; D004047:Diethyl Pyrocarbonate; D005033:Ethylmaleimide