1LNU

CRYSTAL STRUCTURE OF CLASS II MHC MOLECULE IAb BOUND TO EALPHA3K PEPTIDE

Summary for 1LNU

• Entry DOI: 10.2210/pdb1lnu/pdb
• Related: 2IAD
• Descriptor: H-2 class II histocompatibility antigen, A-B alpha chain, H-2 class II histocompatibility antigen, A beta chain, 2-acetamido-2-deoxy-beta-D-glucopyranose, ... (4 entities in total)
• Functional Keywords: protein-peptide complex, t cell receptor, antigen presentation, sugar binding protein
• Biological source: Mus musculus (house mouse); More
• Total number of polymer chains: 8
• Total formula weight: 184801.64

Authors

Liu, X.,Dai, S.,Crawford, F.,Fruge, R.,Marrack, P.,Kappler, J. (deposition date: 2002-05-03, release date: 2002-08-14, Last modification date: 2023-08-16)

Primary citation

Liu, X.,Dai, S.,Crawford, F.,Fruge, R.,Marrack, P.,Kappler, J.
Alternate interactions define the binding of peptides to the MHC molecule IA(b).
Proc.Natl.Acad.Sci.USA, 99:8820-8825, 2002

PubMed Abstract: We have solved the crystal structure of the MHCII molecule, IA(b), containing an antigenic variant of the major IA(b)-binding peptide derived from the MHCII IEalpha chain. The four MHC pockets at p1, p4, p6, and p9 that usually bind peptide side chains are largely empty because of alanines in the peptide at these positions. The complex is nevertheless very stable, apparently because of unique alternate interactions between the IA(b) and peptide. In particular, there are multiple additional hydrogen bonds between the N-terminal end of the peptide and the IA(b) alpha chain and an extensive hydrogen bond network involving an asparagine at p7 position of the peptide and the IA(b) beta chain. By using knowledge of the shape and size of the traditional side chain binding pockets and the additional possible interactions, an IA(b) peptide-binding motif can be deduced that agrees well with the sequences of known IA(b)-binding peptides.

PubMed: 12084926
DOI: 10.1073/pnas.132272099

Experimental method

X-RAY DIFFRACTION (2.5 Å)