title: Type II fatty acid synthesis is essential for the replication of Chlamydia trachomatis.
abstract: The major phospholipid classes of the obligate intracellular bacterial parasite Chlamydia trachomatis are the same as its eukaryotic host except that they also contain chlamydia-made branched-chain fatty acids in the 2-position. Genomic analysis predicts that C. trachomatis is capable of type II fatty acid synthesis (FASII). AFN-1252 was deployed as a chemical tool to specifically inhibit the enoyl-acyl carrier protein reductase (FabI) of C. trachomatis to determine whether chlamydial FASII is essential for replication within the host. The C. trachomatis FabI (CtFabI) is a homotetramer and exhibited typical FabI kinetics, and its expression complemented an Escherichia coli fabI(Ts) strain. AFN-1252 inhibited CtFabI by binding to the FabI·NADH complex with an IC50 of 0.9 μM at saturating substrate concentration. The x-ray crystal structure of the CtFabI·NADH·AFN-1252 ternary complex revealed the specific interactions between the drug, protein, and cofactor within the substrate binding site. AFN-1252 treatment of C. trachomatis-infected HeLa cells at any point in the infectious cycle caused a decrease in infectious titers that correlated with a decrease in branched-chain fatty acid biosynthesis. AFN-1252 treatment at the time of infection prevented the first cell division of C. trachomatis, although the cell morphology suggested differentiation into a metabolically active reticulate body. These results demonstrate that FASII activity is essential for C. trachomatis proliferation within its eukaryotic host and validate CtFabI as a therapeutic target against C. trachomatis.
authors: From the Departments of Infectious Diseases and.
authors: Jiangwei
authors: J
authors: Yao
authors: the Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, Tennessee 38163, and the Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt.
authors: Yasser M
authors: YM
authors: Abdelrahman
authors: Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 48105.
authors: Rosanna M
authors: RM
authors: Robertson
authors: the Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, Tennessee 38163, and.
authors: John V
authors: JV
authors: Cox
authors: the Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, Tennessee 38163, and.
authors: Robert J
authors: RJ
authors: Belland
authors: Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 48105.
authors: Stephen W
authors: SW
authors: White
authors: From the Departments of Infectious Diseases and charles.rock@stjude.org.
authors: Charles O
authors: CO
authors: Rock
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D001572:Benzofurans / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects; D002692:Chlamydia trachomatis / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D018360:Crystallography, X-Ray; D050753:Enoyl-(Acyl-Carrier-Protein) Reductase (NADH) / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D054889:Fatty Acid Synthase, Type II / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D005227:Fatty Acids / Q000096:biosynthesis*; D005798:Genes, Bacterial; D006367:HeLa Cells; D006801:Humans; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D020836:Protein Structure, Quaternary; D011753:Pyrones / Q000494:pharmacology; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: C521531:API 1252; D001426:Bacterial Proteins; D001572:Benzofurans; D004791:Enzyme Inhibitors; D005227:Fatty Acids; D011753:Pyrones; D011994:Recombinant Proteins; D050753:Enoyl-(Acyl-Carrier-Protein) Reductase (NADH); D054889:Fatty Acid Synthase, Type II
keywords: Bacterial Metabolism; Chlamydia trachomatis; Enzyme Inhibitor; Fatty Acid Synthase (FAS); Fatty Acid Synthesis; Glycerophospholipid