Ernst Ruska-Center for Microscopy and Spectroscopy with Electrons (ER-C-3): Structural Biology, Forschungszentrum Jülich, 52425 Jülich, Germany.
Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, 55128 Mainz, Germany.
Cell Rep. 2024 Sep 24;43(9):114657. doi: 10.1016/j.celrep.2024.114657. Epub 2024 Aug 28.
SynDLP, a dynamin-like protein (DLP) encoded in the cyanobacterium Synechocystis sp. PCC 6803, has recently been identified to be structurally highly similar to eukaryotic dynamins. To elucidate structural changes during guanosine triphosphate (GTP) hydrolysis, we solved the cryoelectron microscopy (cryo-EM) structures of oligomeric full-length SynDLP after addition of guanosine diphosphate (GDP) at 4.1 Å and GTP at 3.6-Å resolution as well as a GMPPNP-bound dimer structure of a minimal G-domain construct of SynDLP at 3.8-Å resolution. In comparison with what has been seen in the previously resolved apo structure, we found that the G-domain is tilted upward relative to the stalk upon GTP hydrolysis and that the G-domain dimerizes via an additional extended dimerization domain not present in canonical G-domains. When incubated with lipid vesicles, we observed formation of irregular tubular SynDLP assemblies that interact with negatively charged lipids. Here, we provide the structural framework of a series of different functional SynDLP assembly states during GTP turnover.
SynDLP 是一种在集胞藻 PCC 6803 中编码的与动力蛋白相关的蛋白（DLP），最近被鉴定为与真核生物动力蛋白在结构上高度相似。为了阐明 GTP 水解过程中的结构变化，我们解析了添加 GDP 后的全长 SynDLP 三聚体在 4.1 Å 和添加 GTP 后的 3.6-Å 分辨率的冷冻电镜（cryo-EM）结构，以及一个最小 G 结构域构建体的 GMPPNP 结合二聚体结构在 3.8-Å 分辨率。与之前解析的 apo 结构相比，我们发现 G 结构域在 GTP 水解时相对于茎向上倾斜，并且 G 结构域通过不在典型 G 结构域中存在的额外扩展二聚化结构域二聚化。当与脂质囊泡孵育时，我们观察到形成不规则管状的 SynDLP 组装体，与带负电荷的脂质相互作用。在这里，我们提供了在 GTP 周转过程中一系列不同功能的 SynDLP 组装状态的结构框架。
