Functional characterization of the acyl carrier protein (PfACP) and beta-ketoacyl ACP synthase III (PfKASIII) from Plasmodium falciparum.
The genome of the malaria parasite, Plasmodium falciparum, appears to contain the proteins necessary for a Type II dissociated fatty acid biosynthetic system. Here we report the functional characterization of two proteins from this system. Purified recombinant acyl carrier protein (ACP) and beta-ketoacyl-ACP synthase III (KASIII) from P. falciparum are soluble and active in a truncated form. Malarial ACP is activated by the addition of a 4'-phosphopantetheine prosthetic group derived from coenzyme A, generating holo-PfACP. Holo-PfACP is an effective substrate for the transacylase activity of PfKASIII, but substitution of a key active site cysteine in PfKASIII to alanine or serine abolishes enzymatic activity. During the schizont stage of parasite development, there is a significant up-regulation of the mRNAs corresponding to these proteins, indicating an important metabolic requirement for fatty acids during this stage.
Waters
Norman C
NC
Division of Experimental Therapeutics, Walter Reed Army Institute of Research, Silver Spring, MD 20910-5100, USA.
Kopydlowski
Karen M
KM
Guszczynski
Tadeusz
T
Wei
Lan
L
Sellers
Patrice
P
Ferlan
Jill T
JT
Lee
Patricia J
PJ
Li
Zhiyu
Z
Woodard
Cassandra L
CL
Shallom
Shamira
S
Gardner
Malcolm J
MJ
Prigge
Sean T
ST
D015099:3-Oxoacyl-(Acyl-Carrier-Protein) Synthase / Q000235:genetics / Q000378:metabolism*; D000213:Acyl Carrier Protein / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D003001:Cloning, Molecular; D064429:Fatty Acid Synthases / Q000235:genetics; D005227:Fatty Acids / Q000096:biosynthesis; D020035:Holoenzymes / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D010204:Pantetheine / Q000031:analogs & derivatives* / Q000378:metabolism; D010963:Plasmodium falciparum / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D016415:Sequence Alignment
D000213:Acyl Carrier Protein; D005227:Fatty Acids; D020035:Holoenzymes; D011994:Recombinant Proteins; D010204:Pantetheine; C077402:3-ketoacyl-acyl carrier protein synthase III; D015099:3-Oxoacyl-(Acyl-Carrier-Protein) Synthase; D064429:Fatty Acid Synthases; C003129:4'-phosphopantetheine