Variable MHC class I engagement by Ly49 natural killer cell receptors demonstrated by the crystal structure of Ly49C bound to H-2K(b).

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TitleVariable MHC class I engagement by Ly49 natural killer cell receptors demonstrated by the crystal structure of Ly49C bound to H-2K(b).
Publication TypeJournal Article
Year of Publication2003
AuthorsDam, J, Guan, R, Natarajan, K, Dimasi, N, Chlewicki, LK, Kranz, DM, Schuck, P, Margulies, DH, Mariuzza, RA
JournalNat Immunol
Volume4
Issue12
Pagination1213-22
Date Published2003 Dec
ISSN1529-2908
KeywordsAnimals, Antigens, Ly, Crystallography, X-Ray, Dimerization, H-2 Antigens, Killer Cells, Natural, Lectins, C-Type, Major Histocompatibility Complex, NK Cell Lectin-Like Receptor Subfamily A, Protein Binding, Protein Structure, Quaternary, Receptors, NK Cell Lectin-Like, Substrate Specificity
Abstract

The Ly49 family of natural killer (NK) receptors regulates NK cell function by sensing major histocompatibility complex (MHC) class I. Ly49 receptors show complex patterns of MHC class I cross-reactivity and, in certain cases, peptide selectivity. To investigate whether specificity differences result from topological differences in MHC class I engagement, we determined the structure of the peptide-selective receptor Ly49C in complex with H-2K(b). The Ly49C homodimer binds two MHC class I molecules in symmetrical way, a mode distinct from that of Ly49A, which binds MHC class I asymmetrically. Ly49C does not directly contact the MHC-bound peptide. In addition, MHC crosslinking by Ly49C was demonstrated in solution. We propose a dynamic model for Ly49-MHC class I interactions involving conformational changes in the receptor, whereby variations in Ly49 dimerization mediate different MHC-binding modes.

DOI10.1038/ni1006
Alternate JournalNat. Immunol.
PubMed ID14595439