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From Proteopedia
Human Protein Farnesyltransferase Complexed with Inhibitor Compound STN-48 And FPP Analog at 1.8A Resolution
Structural highlights
Function[PFTA_HUMAN] Catalyzes the transfer of a farnesyl or geranyl-geranyl moiety from farnesyl or geranyl-geranyl pyrophosphate to a cysteine at the fourth position from the C-terminus of several proteins having the C-terminal sequence Cys-aliphatic-aliphatic-X. The alpha subunit is thought to participate in a stable complex with the substrate. The beta subunit binds the peptide substrate. Through RAC1 prenylation and activation may positively regulate neuromuscular junction development downstream of MUSK (By similarity). [PFTB_HUMAN] Catalyzes the transfer of a farnesyl moiety from farnesyl pyrophosphate to a cysteine at the fourth position from the C-terminus of several proteins. The beta subunit is responsible for peptide-binding. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe post-translational farnesylation of proteins serves to anchor a subset of intracellular proteins to membranes in eukaryotic organisms and also promotes protein-protein interactions. This enzymatic reaction is carried out by protein farnesyltransferase (PFT), which catalyzes the transfer of a 15-carbon isoprenoid lipid unit, a farnesyl group, from farnesyl pyrophosphate to the C-termini of proteins containing a CaaX motif. Inhibition of PFT is lethal to the pathogenic protozoa Plasmodium falciparum. Previously, we have shown that parasites resistant to a tetrahydroquinoline (THQ)-based PFT inhibitor BMS-388891 have mutations leading to amino acid substitutions in PFT that map to the peptide substrate binding domain. We now report the selection of parasites resistant to another THQ PFT inhibitor BMS-339941. In whole cell assays sensitivity to BMS-339941 was reduced by 33-fold in a resistant clone, and biochemical analysis demonstrated a corresponding 33-fold increase in the BMS-339941 K(i) for the mutant PFT enzyme. More detailed kinetic analysis revealed that the mutant enzyme required higher concentration of peptide and farnesyl pyrophosphate substrates for optimum catalysis. Unlike previously characterized parasites resistant to BMS-388891, the resistant parasites have a mutation which is predicted to be in a distinct location of the enzymatic pocket, near the farnesyl pyrophosphate binding pocket. This is the first description of a mutation from any species affecting the farnesyl pyrophosphate binding pocket with reduced efficacy of PFT inhibitors. These data provide further support that PFT is the target of THQ inhibitors in P. falciparum and suggest that PFT inhibitors should be combined with other antimalarial agents to minimize the development of resistant parasites. Resistance mutations at the lipid substrate binding site of Plasmodium falciparum protein farnesyltransferase.,Eastman RT, White J, Hucke O, Yokoyama K, Verlinde CL, Hast MA, Beese LS, Gelb MH, Rathod PK, Van Voorhis WC Mol Biochem Parasitol. 2007 Mar;152(1):66-71. Epub 2006 Dec 22. PMID:17208314[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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