Crystal structure of human triggering receptor expressed on myeloid cells 1 (TREM-1) at 1.47 A

J Mol Biol. 2004 Sep 24;342(4):1237-48. doi: 10.1016/j.jmb.2004.07.089.


The triggering receptor expressed on myeloid cells (TREM) family of single extracellular immunoglobulin receptors includes both activating and inhibitory isoforms whose ligands are unknown. TREM-1 activation amplifies the Toll-like receptor initiated responses to invading pathogens allowing the secretion of pro-inflammatory chemokines and cytokines. Hence, TREM-1 amplifies the inflammation induced by both bacteria and fungi, and thus represents a potential therapeutic target. We report the crystal structure of the human TREM-1 extracellular domain at 1.47 A resolution. The overall fold places it within the V-type immunoglobulin domain family and reveals close homology with Ig domains from antibodies, T-cell receptors and other activating receptors, such as NKp44. With the additional use of analytical ultracentrifugation and 1H NMR spectroscopy of both human and mouse TREM-1, we have conclusively demonstrated the monomeric state of this extracellular ectodomain in solution and, presumably, of the TREM family in general.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Crystallography, X-Ray
  • Humans
  • Membrane Glycoproteins / chemistry*
  • Models, Molecular
  • Molecular Sequence Data
  • Nuclear Magnetic Resonance, Biomolecular
  • Receptors, Immunologic / chemistry*
  • Sequence Homology, Amino Acid
  • Triggering Receptor Expressed on Myeloid Cells-1
  • Ultracentrifugation


  • Membrane Glycoproteins
  • Receptors, Immunologic
  • TREM1 protein, human
  • Triggering Receptor Expressed on Myeloid Cells-1