5N78

Crystal structure of the cytosolic domain of the CorA Mg2+ channel from Escherichia coli in complex with magnesium and cobalt hexammine

Summary for 5N78

• Entry DOI: 10.2210/pdb5n78/pdb
• Descriptor: Magnesium transport protein CorA, MAGNESIUM ION, COBALT HEXAMMINE(III), ... (5 entities in total)
• Functional Keywords: homopentamer complex transport membrane, transport protein
• Biological source: Escherichia coli
• Cellular location: Cell inner membrane ; Multi-pass membrane protein : P0ABI4
• Total number of polymer chains: 5
• Total formula weight: 152114.61

Authors

Lerche, M.,Sandhu, H.,Flockner, L.,Hogbom, M.,Rapp, M. (deposition date: 2017-02-20, release date: 2017-07-12, Last modification date: 2024-05-08)

Primary citation

Lerche, M.,Sandhu, H.,Flockner, L.,Hogbom, M.,Rapp, M.
Structure and Cooperativity of the Cytosolic Domain of the CorA Mg(2+) Channel from Escherichia coli.
Structure, 25:1175-1186.e4, 2017

PubMed Abstract: Structures of the Mg bound (closed) and apo (open) states of CorA suggests that channel gating is accomplished by rigid-body motions between symmetric and asymmetric assemblies of the cytosolic portions of the five subunits in response to ligand (Mg) binding/unbinding at interfacial sites. Here, we structurally and biochemically characterize the isolated cytosolic domain from Escherichia coli CorA. The data reveal an Mg-ligand binding site located in a novel position between each of the five subunits and two Mg ions trapped inside the pore. Soaking experiments show that cobalt hexammine outcompetes Mg at the pore site closest to the membrane. This represents the first structural information of how an analog of hexa-hydrated Mg (and competitive inhibitor of CorA) associates to the CorA pore. Biochemical data on the isolated cytoplasmic domain and full-length protein suggests that gating of the CorA channel is governed cooperatively.

PubMed: 28669631
DOI: 10.1016/j.str.2017.05.024

Experimental method

X-RAY DIFFRACTION (2.85 Å)