1G5X

The Structure of Beta-Ketoacyl-[Acyl Carrier Protein] Synthase I

Summary for 1G5X

• Entry DOI: 10.2210/pdb1g5x/pdb
• Related: 1FJ4 1FJ8
• Descriptor: BETA-KETOACYL ACYL CARRIER PROTEIN SYNTHASE I (2 entities in total)
• Functional Keywords: enzyme, gene duplication, transferase
• Biological source: Escherichia coli
• Cellular location: Cytoplasm: P0A953
• Total number of polymer chains: 4
• Total formula weight: 170624.81

Authors

Zhang, Y.M.,Rao, M.S.,Heath, R.J.,Price, A.C.,Olson, A.J.,Rock, C.O.,White, S.W. (deposition date: 2000-11-02, release date: 2000-11-15, Last modification date: 2024-04-03)

Primary citation

Zhang, Y.M.,Rao, M.S.,Heath, R.J.,Price, A.C.,Olson, A.J.,Rock, C.O.,White, S.W.
Identification and analysis of the acyl carrier protein (ACP) docking site on beta-ketoacyl-ACP synthase III.
J.Biol.Chem., 276:8231-8238, 2001

PubMed Abstract: The molecular details that govern the specific interactions between acyl carrier protein (ACP) and the enzymes of fatty acid biosynthesis are unknown. We investigated the mechanism of ACP-protein interactions using a computational analysis to dock the NMR structure of ACP with the crystal structure of beta-ketoacyl-ACP synthase III (FabH) and experimentally tested the model by the biochemical analysis of FabH mutants. The activities of the mutants were assessed using both an ACP-dependent and an ACP-independent assay. The ACP interaction surface was defined by mutations that compromised FabH activity in the ACP-dependent assay but had no effect in the ACP-independent assay. ACP docked to a positively charged/hydrophobic patch adjacent to the active site tunnel on FabH, which included a conserved arginine (Arg-249) that was required for ACP docking. Kinetic analysis and direct binding studies between FabH and ACP confirmed the identification of Arg-249 as critical for FabH-ACP interaction. Our experiments reveal the significance of the positively charged/hydrophobic patch located adjacent to the active site cavities of the fatty acid biosynthesis enzymes and the high degree of sequence conservation in helix II of ACP across species.

PubMed: 11078736
DOI: 10.1074/jbc.M008042200

Experimental method

X-RAY DIFFRACTION (2.45 Å)