2BBJ

Crystal structure of the CorA Mg2+ transporter

Summary for 2BBJ

• Entry DOI: 10.2210/pdb2bbj/pdb
• Related: 2BBH
• Descriptor: divalent cation transport-related protein (1 entity in total)
• Functional Keywords: transporter, membrane, mg, pentamer, structural genomics, structural genomics consortium, sgc, metal transport-membrane protein complex, metal transport/membrane protein
• Biological source: Thermotoga maritima
• Cellular location: Cell inner membrane; Multi-pass membrane protein: Q9WZ31
• Total number of polymer chains: 5
• Total formula weight: 208901.78

Authors

Lunin, V.V.,Dobrovetsky, E.,Khutoreskaya, G.,Zhang, R.,Joachimiak, A.,Bochkarev, A.,Maguire, M.E.,Edwards, A.M.,Koth, C.M.,Structural Genomics Consortium (SGC) (deposition date: 2005-10-17, release date: 2005-12-13, Last modification date: 2023-08-23)

Primary citation

Lunin, V.V.,Dobrovetsky, E.,Khutoreskaya, G.,Zhang, R.,Joachimiak, A.,Doyle, D.A.,Bochkarev, A.,Maguire, M.E.,Edwards, A.M.,Koth, C.M.
Crystal structure of the CorA Mg2+ transporter
Nature, 440:833-837, 2006

PubMed Abstract: The magnesium ion, Mg2+, is essential for myriad biochemical processes and remains the only major biological ion whose transport mechanisms remain unknown. The CorA family of magnesium transporters is the primary Mg2+ uptake system of most prokaryotes and a functional homologue of the eukaryotic mitochondrial magnesium transporter. Here we determine crystal structures of the full-length Thermotoga maritima CorA in an apparent closed state and its isolated cytoplasmic domain at 3.9 A and 1.85 A resolution, respectively. The transporter is a funnel-shaped homopentamer with two transmembrane helices per monomer. The channel is formed by an inner group of five helices and putatively gated by bulky hydrophobic residues. The large cytoplasmic domain forms a funnel whose wide mouth points into the cell and whose walls are formed by five long helices that are extensions of the transmembrane helices. The cytoplasmic neck of the pore is surrounded, on the outside of the funnel, by a ring of highly conserved positively charged residues. Two negatively charged helices in the cytoplasmic domain extend back towards the membrane on the outside of the funnel and abut the ring of positive charge. An apparent Mg2+ ion was bound between monomers at a conserved site in the cytoplasmic domain, suggesting a mechanism to link gating of the pore to the intracellular concentration of Mg2+.

PubMed: 16598263
DOI: 10.1038/nature04642

Experimental method

X-RAY DIFFRACTION (3.9 Å)