Acetyl-CoA carboxylases (ACCs) are crucial metabolic enzymes and attractive targets for drug discovery. Eukaryotic acetyl-CoA carboxylases are 250 kDa single-chain, multi-domain enzymes and function as dimers and higher oligomers. Their catalytic activity is tightly regulated by phosphorylation and other means. Here we show that yeast ACC is directly phosphorylated by the protein kinase SNF1 at residue Ser1157, which potently inhibits the enzyme. Crystal structure of three ACC central domains (AC3-AC5) shows that the phosphorylated Ser1157 is recognized by Arg1173, Arg1260, Tyr1113 and Ser1159. The R1173A/R1260A double mutant is insensitive to SNF1, confirming that this binding site is crucial for regulation. Electron microscopic studies reveal dramatic conformational changes in the holoenzyme upon phosphorylation, likely owing to the dissociation of the biotin carboxylase domain dimer. The observations support a unified molecular mechanism for the regulation of ACC by phosphorylation as well as by the natural product soraphen A, a potent inhibitor of eukaryotic ACC. These molecular insights enhance our understanding of acetyl-CoA carboxylase regulation and provide a basis for drug discovery.

中文翻译：

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通过磷酸化调节乙酰辅酶A羧化酶的统一分子机制。

乙酰辅酶A羧化酶（ACC）是关键的代谢酶，也是药物开发的有吸引力的靶标。真核乙酰辅酶A羧化酶是250 kDa的单链，多结构域酶，起二聚体和高级寡聚体的作用。它们的催化活性通过磷酸化和其他方式严格调节。在这里，我们显示酵母ACC在残基Ser1157处被蛋白激酶SNF1直接磷酸化，有效抑制了该酶。三个ACC中心域（AC3-AC5）的晶体结构表明，磷酸化的Ser1157被Arg1173，Arg1260，Tyr1113和Ser1159识别。R1173A / R1260A双重突变体对SNF1不敏感，证实该结合位点对于调节至关重要。电子显微镜研究发现，磷酸化后全酶的构象发生了显着变化，可能是由于生物素羧化酶域二聚体的解离。这些发现支持了通过磷酸化以及天然产物soraphen A（一种有效的真核ACC抑制剂）调节ACC的统一分子机制。这些分子洞察力增强了我们对乙酰辅酶A羧化酶调节的理解，并为药物发现提供了基础。