Crystal Structure of a Divalent Metal Ion Transporter CorA at 2.9 Angstrom Resolution
Said Eshaghi,1*
Damian Niegowski,1,2*
Andreas Kohl,1
Daniel Martinez Molina,1,2
Scott A. Lesley,3
Pär Nordlund1
CorA family members are ubiquitously distributed transporters of divalent metal cations and are considered to be the primary Mg2+ transporter of Bacteria and Archaea. We have determined a 2.9 angstrom resolution structure of CorA from Thermotoga maritima that reveals a pentameric cone–shaped protein. Two potential regulatory metal binding sites are found in the N-terminal domain that bind both Mg2+ and Co2+. The structure of CorA supports an efflux system involving dehydration and rehydration of divalent metal ions potentially mediated by a ring of conserved aspartate residues at the cytoplasmic entrance and a carbonyl funnel at the periplasmic side of the pore.
1 Division of Biophysics, Department of Medical Biochemistry and Biophysics, Karolinska Institute, SE-171 77 Stockholm, Sweden.
2 Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden.
3 Joint Center for Structural Genomics and Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA.
* These authors contributed equally to this work.
To whom correspondence should be addressed. E-mail: Par.Nordlund{at}ki.se (P.N.); Said.Eshaghi{at}ki.se (S.E.)
