8GCL

Cryo-EM structure of hAQP2 in DDM

Summary for 8GCL

• Entry DOI: 10.2210/pdb8gcl/pdb
• EMDB information: 29934
• Descriptor: Aquaporin-2 (1 entity in total)
• Functional Keywords: channel, membrane protein
• Biological source: Homo sapiens (human)
• Total number of polymer chains: 1
• Total formula weight: 28862.39

Authors

Kamegawa, A.,Suzuki, S.,Nishikawa, K.,Numoto, N.,Suzuki, H.,Fujiyoshi, Y. (deposition date: 2023-03-02, release date: 2023-06-21, Last modification date: 2024-06-19)

Primary citation

Kamegawa, A.,Suzuki, S.,Suzuki, H.,Nishikawa, K.,Numoto, N.,Fujiyoshi, Y.
Structural analysis of the water channel AQP2 by single-particle cryo-EM.
J.Struct.Biol., 215:107984-107984, 2023

PubMed Abstract: Water channels, which are small membrane proteins almost entirely buried in lipid membranes, are challenging research targets for single-particle cryo-electron microscopy (cryo-EM), a powerful technique routinely used to determine the structures of membrane proteins. Because the single-particle method enables structural analysis of a whole protein with flexible parts that interfere with crystallization, we have focused our efforts on analyzing water channel structures. Here, utilizing this system, we analyzed the structure of full-length aquaporin-2 (AQP2), a primary regulator of vasopressin-dependent reabsorption of water at the renal collecting ducts. The 2.9 Å resolution map revealed a cytoplasmic extension of the cryo-EM density that was presumed to be the highly flexible C-terminus at which the localization of AQP2 is regulated in the renal collecting duct cells. We also observed a continuous density along the common water pathway inside the channel pore and lipid-like molecules at the membrane interface. Observations of these constructions in the AQP2 structure analyzed without any fiducial markers (e.g., a rigidly bound antibody) indicate that single-particle cryo-EM will be useful for investigating water channels in native states as well as in complexes with chemical compounds.

PubMed: 37315821
DOI: 10.1016/j.jsb.2023.107984

Experimental method

ELECTRON MICROSCOPY (2.89 Å)