1FV1

STRUCTURAL BASIS FOR THE BINDING OF AN IMMUNODOMINANT PEPTIDE FROM MYELIN BASIC PROTEIN IN DIFFERENT REGISTERS BY TWO HLA-DR2 ALLELES

1FV1 の概要

• エントリーDOI: 10.2210/pdb1fv1/pdb
• 分子名称: MAJOR HISTOCOMPATIBILITY COMPLEX ALPHA CHAIN, MAJOR HISTOCOMPATIBILITY COMPLEX BETA CHAIN, MYELIN BASIC PROTEIN, ... (6 entities in total)
• 機能のキーワード: mhc class ii dr2a, immune system
• 由来する生物種: Homo sapiens (human); 詳細
• 細胞内の位置: Cell membrane; Single-pass type I membrane protein: P01903 Q30154; Myelin membrane; Peripheral membrane protein; Cytoplasmic side: P02686
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 91662.43

構造登録者

Li, H.,Mariuzza, A.R.,Li, Y.,Martin, R. (登録日: 2000-09-18, 公開日: 2000-09-27, 最終更新日: 2011-07-13)

主引用文献

Li, Y.,Li, H.,Martin, R.,Mariuzza, R.A.
Structural basis for the binding of an immunodominant peptide from myelin basic protein in different registers by two HLA-DR2 proteins.
J.Mol.Biol., 304:177-188, 2000

PubMed Abstract: Susceptibility to multiple sclerosis (MS) is associated with certain MHC class II haplotypes, in particular HLA-DR2. Two DR beta chains, DRB1*1501 and DRB5*0101, are co-expressed in the HLA-DR2 haplotype, resulting in the formation of two functional cell surface heterodimers, HLA-DR2a (DRA*0101, DRB5*0101) and HLA-DR2b (DRA*0101, DRB1*1501). Both isotypes can present an immunodominant peptide of myelin basic protein (MBP 84-102) to MBP-specific T cells from MS patients. We have determined the crystal structure of HLA-DR2a complexed with MBP 86-105 to 1.9 A resolution. A comparison of this structure with that of HLA-DR2b complexed with MBP 85-99, reported previously, reveals that the peptide register is shifted by three residues, such that the MBP peptide is bound in strikingly different conformations by the two MHC molecules. This shift in binding register is attributable to a large P1 pocket in DR2a, which accommodates Phe92, in conjunction with a relatively shallow P4 pocket, which is occupied by Ile95. In DR2b, by contrast, the small P1 pocket accommodates Val89, while the deep P4 pocket is filled by Phe92. In both complexes, however, the C-terminal half of the peptide is positioned higher in the binding groove than in other MHC class II/peptide structures. As a result of the register shift, different side-chains of the MBP peptide are displayed for interaction with T cell receptors in the DR2a and DR2b complexes. These results demonstrate that MHC molecules can impose different alignments and conformations on the same bound peptide as a consequence of topological differences in their peptide-binding sites, thereby creating distinct T cell epitopes.

PubMed: 11080454
DOI: 10.1006/jmbi.2000.4198

実験手法

X-RAY DIFFRACTION (1.9 Å)