2l0q

NMR Solution Structure of Vibrio harveyi Acyl Carrier Protein (ACP)

spinqualitylabelsall models 2l0q, 20 NMR models Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2l0q is a 1 chain structure with sequence from Vibrio harveyi 1da3. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Gene: acpP, VME_27770 (Vibrio harveyi 1DA3) Resources: FirstGlance, OCA, RCSB, PDBsum Function [D0XCG4_VIBHA] Carrier of the growing fatty acid chain in fatty acid biosynthesis.[HAMAP-Rule:MF_01217][RuleBase:RU003545] 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 PubMed Bacterial acyl carrier protein (ACP) is a highly anionic, 9 kDa protein that functions as a cofactor protein in fatty acid biosynthesis. Escherichia coli ACP is folded at neutral pH and in the absence of divalent cations, while Vibrio harveyi ACP, which is very similar at 86% sequence identity, is unfolded under the same conditions. V. harveyi ACP adopts a folded conformation upon the addition of divalent cations such as Ca(2+) and Mg(2+) and a mutant, A75H, was previously identified that restores the folded conformation at pH 7 in the absence of divalent cations. In this study we sought to understand the unique folding behavior of V. harveyi ACP using NMR spectroscopy and biophysical methods. The NMR solution structure of V. harveyi ACP A75H displays the canonical ACP structure with four helices surrounding a hydrophobic core, with a narrow pocket closed off from the solvent to house the acyl chain. His-75, which is charged at neutral pH, participates in a stacking interaction with Tyr-71 in the far C-terminal end of helix IV. pH titrations and the electrostatic profile of ACP suggest that V. harveyi ACP is destabilized by anionic charge repulsion around helix II that can be partially neutralized by His-75 and is further reduced by divalent cation binding. This is supported by differential scanning calorimetry data which indicate that calcium binding further increases the melting temperature of V. harveyi ACP A75H by approximately 20 degrees C. Divalent cation binding does not alter ACP dynamics on the ps-ns timescale as determined by (15)N NMR relaxation experiments, however, it clearly stabilizes the protein fold as observed by hydrogen-deuterium exchange studies. Finally, we demonstrate that the E. coli ACP H75A mutant is similarly unfolded as wild-type V. harveyi ACP, further stressing the importance of this particular residue for proper protein folding. NMR solution structure and biophysical characterization of Vibrio harveyi acyl carrier protein A75H: effects of divalent metal ions.,Chan DI, Chu BC, Lau CK, Hunter HN, Byers DM, Vogel HJ J Biol Chem. 2010 Oct 1;285(40):30558-66. Epub 2010 Jul 21. PMID:20659901 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Acyl carrier protein

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