Crystal structure of an asymmetric trimer of a bacterial glutamate transporter homolog

Nat Struct Mol Biol. 2012 Feb 12;19(3):355-7. doi: 10.1038/nsmb.2233.


We report a structure of a trimeric glutamate transporter homolog from Pyrococcus horikoshii with two protomers in an inward facing state and the third in an intermediate conformation between the outward and inward facing states. The intermediate shows a cavity in the thinnest region of the transporter, which is potentially accessible to extracellular and cytoplasmic solutions. Our findings suggest a structural principle by which transport intermediates may mediate uncoupled permeation of polar solutes.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Amino Acid Transport System X-AG / chemistry*
  • Crystallography, X-Ray
  • Models, Molecular
  • Protein Structure, Quaternary*
  • Protein Structure, Tertiary
  • Pyrococcus horikoshii / chemistry*


  • Amino Acid Transport System X-AG

Associated data

  • PDB/3V8F
  • PDB/3V8G