ジャーナル: Nature / 年: 2018 タイトル: Structural basis for regulation of human acetyl-CoA carboxylase. 著者: Moritz Hunkeler / Anna Hagmann / Edward Stuttfeld / Mohamed Chami / Yakir Guri / Henning Stahlberg / Timm Maier / 要旨: Acetyl-CoA carboxylase catalyses the ATP-dependent carboxylation of acetyl-CoA, a rate-limiting step in fatty acid biosynthesis. Eukaryotic acetyl-CoA carboxylases are large, homodimeric multienzymes. ...Acetyl-CoA carboxylase catalyses the ATP-dependent carboxylation of acetyl-CoA, a rate-limiting step in fatty acid biosynthesis. Eukaryotic acetyl-CoA carboxylases are large, homodimeric multienzymes. Human acetyl-CoA carboxylase occurs in two isoforms: the metabolic, cytosolic ACC1, and ACC2, which is anchored to the outer mitochondrial membrane and controls fatty acid β-oxidation. ACC1 is regulated by a complex interplay of phosphorylation, binding of allosteric regulators and protein-protein interactions, which is further linked to filament formation. These filaments were discovered in vitro and in vivo 50 years ago, but the structural basis of ACC1 polymerization and regulation remains unknown. Here, we identify distinct activated and inhibited ACC1 filament forms. We obtained cryo-electron microscopy structures of an activated filament that is allosterically induced by citrate (ACC-citrate), and an inactivated filament form that results from binding of the BRCT domains of the breast cancer type 1 susceptibility protein (BRCA1). While non-polymeric ACC1 is highly dynamic, filament formation locks ACC1 into different catalytically competent or incompetent conformational states. This unique mechanism of enzyme regulation via large-scale conformational changes observed in ACC1 has potential uses in engineering of switchable biosynthetic systems. Dissecting the regulation of acetyl-CoA carboxylase opens new paths towards counteracting upregulation of fatty acid biosynthesis in disease.
電子線照射量: 80 e/Å2 フィルム・検出器のモデル: GATAN K2 SUMMIT (4k x 4k) 詳細: Collected in movie-mode with total dose of 80 e-/A2 for a total of 80 frames. Frames 3-22 were used for final reconstruction.
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解析
ソフトウェア
名称
バージョン
分類
PHENIX
1.11.1_2575
精密化
PHENIX
1.11.1_2575
精密化
EMソフトウェア
名称: RELION / バージョン: 2.01 / カテゴリ: 3次元再構成
CTF補正
タイプ: PHASE FLIPPING AND AMPLITUDE CORRECTION
対称性
点対称性: C2 (2回回転対称)
3次元再構成
解像度: 4.6 Å / 解像度の算出法: FSC 0.143 CUT-OFF / 粒子像の数: 48483 / 対称性のタイプ: POINT
精密化
立体化学のターゲット値: GeoStd + Monomer Library 詳細: The clash score value (4.5) reported in the publication associated with this model was obtained directly from phenix.real_space_refine version 1.11.1-2575. We acknowledge that the current ...詳細: The clash score value (4.5) reported in the publication associated with this model was obtained directly from phenix.real_space_refine version 1.11.1-2575. We acknowledge that the current validation toolchain of wwwPDB produces slightly higher values, possibly linked to the handling of cif files (required as this submission contains more than 100.000 atoms) and protons and have locally reproduced this difference by using earlier software versions. The direct cif output of phenix.real_space_refine has been translated using phenix.pdbtools by 1,1,0 (fractional unit cell axes) or 397.808,397.808,0 Angstroms to match the standard EM map frame