title: The structure of an intermediate in class II MHC maturation: CLIP bound to HLA-DR3.
abstract: A complex between HLA-DR3 and a fragment of invariant chain called CLIP was isolated from a human cell line defective in antigen presentation and its X-ray crystal structure determined. Previous data indicate that this complex is an intermediate in class II histocompatibility maturation, occurring between invariant chain-DR3 and antigenic peptide-DR3 complexes. The structure shows that the CLIP fragment binds to DR3 in a way almost identical to that in which antigenic peptides bind class II histocompatibility glycoproteins. The structure is the substrate for the loading of antigenic peptides by an exchange process catalysed by DM.
mesh_terms: D000595:Amino Acid Sequence; D017951:Antigen Presentation; D000944:Antigens, Differentiation, B-Lymphocyte / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D001665:Binding Sites; D002460:Cell Line; D018360:Crystallography, X-Ray; D006681:HLA-D Antigens / Q000737:chemistry / Q000378:metabolism; D015798:HLA-DR1 Antigen / Q000737:chemistry / Q000378:metabolism; D015803:HLA-DR3 Antigen / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D006207:Half-Life; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D006389:Hemagglutinins, Viral / Q000737:chemistry / Q000378:metabolism; D000949:Histocompatibility Antigens Class II / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D006801:Humans; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D011487:Protein Conformation
chemical_list: D000944:Antigens, Differentiation, B-Lymphocyte; C416189:H2-M antigens; D006681:HLA-D Antigens; C084245:HLA-DM antigens; D015798:HLA-DR1 Antigen; D015803:HLA-DR3 Antigen; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D006389:Hemagglutinins, Viral; D000949:Histocompatibility Antigens Class II; C045084:invariant chain