Structural Biology

Toll-Like Receptor Structure Revealed

Science's STKE  26 Jul 2005:
Vol. 2005, Issue 294, pp. tw276
DOI: 10.1126/stke.2942005tw276

Binding of diverse ligands initiates various signaling pathways that play a role in the immune response. Human Toll-like receptor 3 (TLR3) is activated by double-stranded RNA such as those associated with many viruses. The lack of a three-dimensional structure for any TLR has hampered the design of experiments to define their mode of signaling. Choe et al. have determined the TLR3 ectodomain structure at 2.1 angstrom resolution. The ectodomain forms a horseshoe-shaped solenoid that comprises 23 leucine-rich repeats. The inner concave surface and a large portion of the outer surface are covered by carbohydrate. One face is glycosylation-free, which suggests that it may play a role in ligand binding and oligomerization.

J. Choe, M. S. Kelker, I. A. Wilson, Crystal structure of human Toll-like receptor 3 (TLR3) ectodomain. Science 309, 581-585 (2005). [Abstract] [Full Text]