2HN2

Crystal structure of the CorA Mg2+ transporter homologue from T. maritima in complex with divalent cations

Summary for 2HN2

• Entry DOI: 10.2210/pdb2hn2/pdb
• Related: 2BBH 2BBJ 2HN1 2IUB
• Descriptor: Magnesium transport protein corA, CALCIUM ION (2 entities in total)
• Functional Keywords: integral membrane protein; metal transporter protein; divalent cations, metal transport
• Biological source: Thermotoga maritima
• Total number of polymer chains: 5
• Total formula weight: 209422.79

Authors

Payandeh, J.,Pai, E.F. (deposition date: 2006-07-11, release date: 2006-08-29, Last modification date: 2023-08-30)

Primary citation

Payandeh, J.,Pai, E.F.
A structural basis for Mg(2+) homeostasis and the CorA translocation cycle.
Embo J., 25:3762-3773, 2006

PubMed Abstract: We describe the CorA Mg(2+) transporter homologue from Thermotoga maritima in complex with 12 divalent cations at 3.7 A resolution. One metal is found near the universally conserved GMN motif, apparently stabilized within the transmembrane region. This portion of the selectivity filter might discriminate between the size and preferred coordination geometry of hydrated substrates. CorA may further achieve specificity by requiring the sequential dehydration of substrates along the length of its approximately 55 A long pore. Ten metal sites identified within the cytoplasmic funnel domain are linked to long extensions of the pore helices and regulate the transport status of CorA. We have characterized this region as an intrinsic divalent cation sensor and provide evidence that it functions as a Mg(2+)-specific homeostatic molecular switch. A proteolytic protection assay, biophysical data, and comparison to a soluble domain structure from Archaeoglobus fulgidus have revealed the potential reaction coordinate for this diverse family of transport proteins.

PubMed: 16902408
DOI: 10.1038/sj.emboj.7601269

Experimental method

X-RAY DIFFRACTION (3.7 Å)