|Title||Crystal structure of a SLC11 (NRAMP) transporter reveals the basis for transition-metal ion transport.|
|Publication Type||Journal Article|
|Year of Publication||2014|
|Authors||Ehrnstorfer, I. A., E. R. Geertsma, E. Pardon, J. Steyaert, and R. Dutzler|
|Journal||Nat Struct Mol Biol|
|Date Published||2014 Nov|
|Keywords||Amino Acid Sequence, Amino Acid Transport Systems, Bacterial Proteins, Binding Sites, Cadmium, Cation Transport Proteins, Cations, Divalent, Conserved Sequence, Crystallography, X-Ray, Escherichia coli, Gene Expression, Humans, Ion Transport, Iron, Manganese, Models, Molecular, Molecular Sequence Data, Protein Binding, Protein Conformation, Recombinant Proteins, Staphylococcus, Structural Homology, Protein, Substrate Specificity, Transcription Factors|
Members of the SLC11 (NRAMP) family transport iron and other transition-metal ions across cellular membranes. These membrane proteins are present in all kingdoms of life with a high degree of sequence conservation. To gain insight into the determinants of ion selectivity, we have determined the crystal structure of Staphylococcus capitis DMT (ScaDMT), a close prokaryotic homolog of the family. ScaDMT shows a familiar architecture that was previously identified in the amino acid permease LeuT. The protein adopts an inward-facing conformation with a substrate-binding site located in the center of the transporter. This site is composed of conserved residues, which coordinate Mn2+, Fe2+ and Cd2+ but not Ca2+. Mutations of interacting residues affect ion binding and transport in both ScaDMT and human DMT1. Our study thus reveals a conserved mechanism for transition-metal ion selectivity within the SLC11 family.
|Alternate Journal||Nat. Struct. Mol. Biol.|
Crystal structure of a SLC11 (NRAMP) transporter reveals the basis for transition-metal ion transport.