7ALO
Structure of B*27:09/photoRL9
Summary for 7ALO
| Entry DOI | 10.2210/pdb7alo/pdb |
| Related | 5IB5 |
| Descriptor | Lymphocyte antigen HLA-B27, Beta-2-microglobulin, Vasoactive intestinal polypeptide receptor 1, ... (9 entities in total) |
| Functional Keywords | mhc (major histocompatibility complex), immune system |
| Biological source | Homo sapiens (Human) More |
| Total number of polymer chains | 6 |
| Total formula weight | 96252.68 |
| Authors | Loll, B.,Lan, H.,Freund, C. (deposition date: 2020-10-07, release date: 2021-06-16, Last modification date: 2024-10-16) |
| Primary citation | Lan, H.,Abualrous, E.T.,Sticht, J.,Fernandez, L.M.A.,Werk, T.,Weise, C.,Ballaschk, M.,Schmieder, P.,Loll, B.,Freund, C. Exchange catalysis by tapasin exploits conserved and allele-specific features of MHC-I molecules. Nat Commun, 12:4236-4236, 2021 Cited by PubMed Abstract: The repertoire of peptides presented by major histocompatibility complex class I (MHC-I) molecules on the cell surface is tailored by the ER-resident peptide loading complex (PLC), which contains the exchange catalyst tapasin. Tapasin stabilizes MHC-I molecules and promotes the formation of stable peptide-MHC-I (pMHC-I) complexes that serve as T cell antigens. Exchange of suboptimal by high-affinity ligands is catalyzed by tapasin, but the underlying mechanism is still elusive. Here we analyze the tapasin-induced changes in MHC-I dynamics, and find the catalyst to exploit two essential features of MHC-I. First, tapasin recognizes a conserved allosteric site underneath the α-helix of MHC-I, 'loosening' the MHC-I F-pocket region that accomodates the C-terminus of the peptide. Second, the scoop loop of tapasin relies on residue L18 to target the MHC-I F-pocket, enabling peptide exchange. Meanwhile, tapasin residue K16 plays an accessory role in catalysis of MHC-I allotypes bearing an acidic F-pocket. Thus, our results provide an explanation for the observed allele-specificity of catalyzed peptide exchange. PubMed: 34244493DOI: 10.1038/s41467-021-24401-4 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.8 Å) |
Structure validation
Download full validation report
