Recognition of host Clr-b by the inhibitory NKR-P1B receptor provides a basis for missing-self recognition.
Balaji, G.R., Aguilar, O.A., Tanaka, M., Shingu-Vazquez, M.A., Fu, Z., Gully, B.S., Lanier, L.L., Carlyle, J.R., Rossjohn, J., Berry, R.(2018) Nat Commun 9: 4623-4623
- PubMed: 30397201 
- DOI: https://doi.org/10.1038/s41467-018-06989-2
- Primary Citation of Related Structures:  
6E7D - PubMed Abstract: 
The interaction between natural killer (NK) cell inhibitory receptors and their cognate ligands constitutes a key mechanism by which healthy tissues are protected from NK cell-mediated lysis. However, self-ligand recognition remains poorly understood within the prototypical NKR-P1 receptor family. Here we report the structure of the inhibitory NKR-P1B receptor bound to its cognate host ligand, Clr-b. NKR-P1B and Clr-b interact via a head-to-head docking mode through an interface that includes a large array of polar interactions. NKR-P1B:Clr-b recognition is extremely sensitive to mutations at the heterodimeric interface, with most mutations severely impacting both Clr-b binding and NKR-P1B receptor function to implicate a low affinity interaction. Within the structure, two NKR-P1B:Clr-b complexes are cross-linked by a non-classic NKR-P1B homodimer, and the disruption of homodimer formation abrogates Clr-b recognition. These data provide an insight into a fundamental missing-self recognition system and suggest an avidity-based mechanism underpins NKR-P1B receptor function.
Organizational Affiliation: 
Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, 3800, Australia.