人过氧化物酶体脂肪酸转运蛋白 ABCD1 在脂质环境中的结构。
Structures of the human peroxisomal fatty acid transporter ABCD1 in a lipid environment.
机构信息
The Hormel Institute, University of Minnesota, Austin, MN, 55912, USA.
出版信息
Commun Biol. 2022 Jan 10;5(1):7. doi: 10.1038/s42003-021-02970-w.
The peroxisomal very long chain fatty acid (VLCFA) transporter ABCD1 is central to fatty acid catabolism and lipid biosynthesis. Its dysfunction underlies toxic cytosolic accumulation of VLCFAs, progressive demyelination, and neurological impairments including X-linked adrenoleukodystrophy (X-ALD). We present cryo-EM structures of ABCD1 in phospholipid nanodiscs in a nucleotide bound conformation open to the peroxisomal lumen and an inward facing conformation open to the cytosol at up to 3.5 Å resolution, revealing details of its transmembrane cavity and ATP dependent conformational spectrum. We identify features distinguishing ABCD1 from its closest homologs and show that coenzyme A (CoA) esters of VLCFAs modulate ABCD1 activity in a species dependent manner. Our data suggest a transport mechanism where the CoA moieties of VLCFA-CoAs enter the hydrophilic transmembrane domain while the acyl chains extend out into the surrounding membrane bilayer. The structures help rationalize disease causing mutations and may aid ABCD1 targeted structure-based drug design.
过氧化物酶体的超长链脂肪酸 (VLCFA) 转运蛋白 ABCD1 是脂肪酸分解代谢和脂质生物合成的核心。其功能障碍导致 VLCFA 在细胞质中毒性积累,进行性脱髓鞘,以及包括 X 连锁肾上腺脑白质营养不良 (X-ALD) 在内的神经损伤。我们展示了 ABCD1 在磷脂纳米盘中结合核苷酸的构象的冷冻电镜结构,该构象向过氧化物酶体腔开放,向细胞质开放的内向构象在高达 3.5 Å 的分辨率下,揭示了其跨膜腔和 ATP 依赖的构象谱的细节。我们确定了将 ABCD1 与其最接近的同源物区分开来的特征,并表明辅因子 A (CoA) 酯的 VLCFAs 以物种依赖的方式调节 ABCD1 的活性。我们的数据表明了一种运输机制,其中 VLCFA-CoA 的 CoA 部分进入亲水性跨膜结构域,而酰基链延伸到周围的膜双层中。这些结构有助于合理解释致病突变,并可能有助于基于 ABCD1 目标的结构药物设计。