PDBsum entry 3l6f

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protein Protein-protein interface(s) links
Immune system/peptide binding protein PDB id
Protein chains
178 a.a. *
191 a.a. *
15 a.a. *
Waters ×196
* Residue conservation analysis
PDB id:
Name: Immune system/peptide binding protein
Title: Structure of mhc class ii molecule hla-dr1 complexed with phosphopeptide mart-1
Structure: Hla class ii histocompatibility antigen, dr alpha chain: a. Fragment: unp residues 26-207. Synonym: mhc class ii antigen dra. Engineered: yes. Hla class ii histocompatibility antigen, drb1-1 b chain: b. Fragment: unp residues 30-221. Synonym: mhc class i antigen drb1 1, Dr-1, dr1.
Source: Homo sapiens. Human. Organism_taxid: 9606. Gene: hla-dra, hla-dra1. Expressed in: escherichia coli. Expression_system_taxid: 469008. Gene: hla-drb1. Expression_system_taxid: 562. Synthetic: yes.
2.10Å     R-factor:   0.212     R-free:   0.249
Authors: Y.Li,R.A.Mariuzza
Key ref: Y.Li et al. (2010). Structural basis for the presentation of tumor-associated MHC class II-restricted phosphopeptides to CD4+ T cells. J Mol Biol, 399, 596-603. PubMed id: 20417641 DOI: 10.1016/j.jmb.2010.04.037
23-Dec-09     Release date:   12-May-10    
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Protein chain
Pfam   ArchSchema ?
P01903  (DRA_HUMAN) -  HLA class II histocompatibility antigen, DR alpha chain
254 a.a.
178 a.a.*
Protein chain
Pfam   ArchSchema ?
P04229  (2B11_HUMAN) -  HLA class II histocompatibility antigen, DRB1-1 beta chain
266 a.a.
191 a.a.*
Protein chain
Pfam   ArchSchema ?
Q16655  (MAR1_HUMAN) -  Melanoma antigen recognized by T-cells 1
118 a.a.
15 a.a.
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 2 residue positions (black crosses)

 Gene Ontology (GO) functional annotation 
  GO annot!
  Cellular component     membrane   2 terms 
  Biological process     immune response   2 terms 


DOI no: 10.1016/j.jmb.2010.04.037 J Mol Biol 399:596-603 (2010)
PubMed id: 20417641  
Structural basis for the presentation of tumor-associated MHC class II-restricted phosphopeptides to CD4+ T cells.
Y.Li, F.R.Depontieu, J.Sidney, T.M.Salay, V.H.Engelhard, D.F.Hunt, A.Sette, S.L.Topalian, R.A.Mariuzza.
Dysregulated protein phosphorylation is a hallmark of malignant transformation. Transformation can generate major histocompatibility complex (MHC)-bound phosphopeptides that are differentially displayed on tumor cells for specific recognition by T cells. To understand how phosphorylation alters the antigenic identity of self peptides and how MHC class II molecules present phosphopeptides for CD4(+)T cell recognition, we determined the crystal structure of a phosphopeptide derived from melanoma antigen recognized by T cells-1 (pMART-1), selectively expressed by human melanomas, in complex with HLA-DR1. The structure revealed that the phosphate moiety attached to the serine residue at position P5 of pMART-1 is available for direct interactions with T cell receptor (TCR), and that the peptide N-terminus adopts an unusual conformation orienting it toward TCR. This structure, combined with measurements of peptide affinity for HLA-DR1 and of peptide-MHC recognition by pMART-1-specific T cells, suggests that TCR recognition is focused on the N-terminal portion of pMART-1. This recognition mode appears to be distinct from that of foreign antigen complexes but is remarkably reminiscent of the way autoreactive TCRs engage self or altered self peptides, consistent with the tolerogenic nature of tumor-host immune interactions.