Schuller Jan M, Beck Florian, Lössl Philip, Heck Albert J R, Förster Friedrich
Department of Molecular Structural Biology, Max-Planck Institute of Biochemistry, Martinsried, Germany.
Biomolecular Mass Spectrometry and Proteomics and Netherlands Proteomics Center, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, The Netherlands.
FEBS Lett. 2016 Mar;590(5):595-604. doi: 10.1002/1873-3468.12091. Epub 2016 Feb 20.
The ubiquitous AAA-ATPase p97 segregates ubiquitylated proteins from their molecular environment. Previous studies of the nucleotide-dependent conformational changes of p97 were inconclusive. Here, we determined its structure in the presence of ADP, AMP-PNP, or ATP-γS at 6.1-7.4 Å resolution using single particle cryo-electron microscopy. Both AAA domains, D1 and D2, assemble into essentially six-fold symmetrical rings. The pore of the D1-ring remains essentially closed under all nucleotide conditions, whereas the D2-ring shows an iris-like opening for ADP. The largest conformational changes of p97 are 'swinging motions' of the N-terminal domains, which may enable segregation of ubiquitylated substrates from their environment.
普遍存在的AAA-ATP酶p97将泛素化蛋白与其分子环境分离。先前关于p97核苷酸依赖性构象变化的研究尚无定论。在此，我们使用单颗粒冷冻电子显微镜在6.1-7.4埃分辨率下测定了其在ADP、AMP-PNP或ATP-γS存在时的结构。两个AAA结构域D1和D2组装成基本六倍对称的环。在所有核苷酸条件下，D1环的孔基本保持关闭，而D2环在结合ADP时呈现出类似虹膜的开口。p97最大的构象变化是N端结构域的“摆动运动”，这可能使泛素化底物与其环境分离。
