4EV6

The complete structure of CorA magnesium transporter from Methanocaldococcus jannaschii

Summary for 4EV6

• Entry DOI: 10.2210/pdb4ev6/pdb
• Related: 4EGW
• Descriptor: Magnesium transport protein CorA, UNDECYL-MALTOSIDE, MAGNESIUM ION, ... (4 entities in total)
• Functional Keywords: membrane protein, cora, magnesium, ion transporter, metal transport
• Biological source: Methanocaldococcus jannaschii
• Cellular location: Cell membrane; Multi-pass membrane protein (By similarity): Q58439
• Total number of polymer chains: 5
• Total formula weight: 203457.05

Authors

Guskov, A.,Nordin, N.,Reynaud, A.,Engman, H.,Lundback, A.-K.,Jong, A.J.O.,Cornvik, T.,Phua, T.,Eshaghi, S. (deposition date: 2012-04-25, release date: 2012-10-31, Last modification date: 2023-11-08)

Primary citation

Guskov, A.,Nordin, N.,Reynaud, A.,Engman, H.,Lundback, A.K.,Jong, A.J.,Cornvik, T.,Phua, T.,Eshaghi, S.
Structural insights into the mechanisms of Mg2+ uptake, transport, and gating by CorA
Proc.Natl.Acad.Sci.USA, 109:18459-18464, 2012

PubMed Abstract: Despite the importance of Mg(2+) for numerous cellular activities, the mechanisms underlying its import and homeostasis are poorly understood. The CorA family is ubiquitous and is primarily responsible for Mg(2+) transport. However, the key questions-such as, the ion selectivity, the transport pathway, and the gating mechanism-have remained unanswered for this protein family. We present a 3.2 Å resolution structure of the archaeal CorA from Methanocaldococcus jannaschii, which is a unique complete structure of a CorA protein and reveals the organization of the selectivity filter, which is composed of the signature motif of this family. The structure reveals that polar residues facing the channel coordinate a partially hydrated Mg(2+) during the transport. Based on these findings, we propose a unique gating mechanism involving a helical turn upon the binding of Mg(2+) to the regulatory intracellular binding sites, and thus converting a polar ion passage into a narrow hydrophobic pore. Because the amino acids involved in the uptake, transport, and gating are all conserved within the entire CorA family, we believe this mechanism is general for the whole family including the eukaryotic homologs.

PubMed: 23091000
DOI: 10.1073/pnas.1210076109

Experimental method

X-RAY DIFFRACTION (3.2 Å)