Qa-2 molecules are peptide receptors of higher stringency than ordinary class I molecules

Item Type:	Article
Title:	Qa-2 molecules are peptide receptors of higher stringency than ordinary class I molecules
Creators Name:	Roetzschke, O. and Falk, K. and Stevanovic, S. and Grahovac, B. and Soloski, M.J. and Jung, G. and Rammensee, H.G.
Abstract:	Class I molecules of the major histocompatibility complex (MHC) transport peptides to the cell surface for surveillance by T cells. Ligand specificity is stringent and differs from allele to allele. Here we report analysis of natural ligands of 'unconventional' glycophosphatidyl-anchored mouse class I molecules, Qa-2. The function of these molecules is unclear; they can serve as recognition structures for 'unrestricted' cytotoxic T cells but have not been found to present peptides to T cells, although the DNA sequence suggests a similar peptide binding groove to that of 'conventional' class I molecules, and other unconventional class I molecules can present antigens in a few cases. Pool sequencing of natural Qa-2 ligands shows that Qa-2 molecules are indeed peptide receptors, having ligand specificity similar to that of conventional class I molecules, that is, a predominant length of nine amino acids, anchor positions, and hydrophobic termination of peptides. But ligand specificity is much more stringent than with other class I molecules: of the nine positions, two are anchors and four have rather limited occupancy.
Keywords:	Amino Acid Sequence, Binding Sites, Histocompatibility Antigens Class I, Inbred C57BL Mice, Molecular Sequence Data, Peptides, Animals, Mice
Source:	Nature
ISSN:	0028-0836
Publisher:	Nature Publishing Group
Volume:	361
Number:	6413
Page Range:	642-644
Date:	18 February 1993
Official Publication:	https://doi.org/10.1038/361642a0
PubMed:	View item in PubMed

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