2L0Q

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

2L0Q の概要

• エントリーDOI: 10.2210/pdb2l0q/pdb
• 分子名称: Acyl carrier protein (1 entity in total)
• 機能のキーワード: acyl carrier protein, fatty acid biosynthesis, acyl chain binding, lipid binding protein
• 由来する生物種: Vibrio harveyi 1DA3
• 細胞内の位置: Cytoplasm (By similarity): D0XCG4
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 8852.66

構造登録者

Chan, D.I.,Chu, B.C.H.,Lau, C.K.Y.,Hunter, H.N.,Byers, D.M.,Vogel, H.J. (登録日: 2010-07-12, 公開日: 2010-07-21, 最終更新日: 2024-05-01)

主引用文献

Chan, D.I.,Chu, B.C.,Lau, C.K.,Hunter, H.N.,Byers, D.M.,Vogel, H.J.
NMR solution structure and biophysical characterization of Vibrio harveyi acyl carrier protein A75H: effects of divalent metal ions.
J.Biol.Chem., 285:30558-30566, 2010

PubMed Abstract: 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 ∼20 °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.

PubMed: 20659901
DOI: 10.1074/jbc.M110.128298

実験手法

SOLUTION NMR