4K8O
CRYSTAL STRUCTURE OF THE ATPASE DOMAIN OF TAP1 WITH ATP (D645N, D651A MUTANT)
Summary for 4K8O
| Entry DOI | 10.2210/pdb4k8o/pdb |
| Descriptor | Antigen peptide transporter 1, ADENOSINE-5'-TRIPHOSPHATE, NICKEL (II) ION, ... (6 entities in total) |
| Functional Keywords | nucleotide binding domain, peptide transport, transport protein |
| Biological source | Rattus norvegicus (brown rat,rat,rats) |
| Cellular location | Endoplasmic reticulum membrane; Multi-pass membrane protein: P36370 |
| Total number of polymer chains | 1 |
| Total formula weight | 30220.74 |
| Authors | Vakkasoglu, A.S.,Grossmann, N.,Hulpke, S.,Abele, R.,Tampe, R.,Gaudet, R. (deposition date: 2013-04-18, release date: 2014-09-03, Last modification date: 2024-11-06) |
| Primary citation | Grossmann, N.,Vakkasoglu, A.S.,Hulpke, S.,Abele, R.,Gaudet, R.,Tampe, R. Mechanistic determinants of the directionality and energetics of active export by a heterodimeric ABC transporter. Nat Commun, 5:5419-5419, 2014 Cited by PubMed Abstract: The ATP-binding cassette (ABC) transporter associated with antigen processing (TAP) participates in immune surveillance by moving proteasomal products into the endoplasmic reticulum (ER) lumen for major histocompatibility complex class I loading and cell surface presentation to cytotoxic T cells. Here we delineate the mechanistic basis for antigen translocation. Notably, TAP works as a molecular diode, translocating peptide substrates against the gradient in a strict unidirectional way. We reveal the importance of the D-loop at the dimer interface of the two nucleotide-binding domains (NBDs) in coupling substrate translocation with ATP hydrolysis and defining transport vectoriality. Substitution of the conserved aspartate, which coordinates the ATP-binding site, decreases NBD dimerization affinity and turns the unidirectional primary active pump into a passive bidirectional nucleotide-gated facilitator. Thus, ATP hydrolysis is not required for translocation per se, but is essential for both active and unidirectional transport. Our data provide detailed mechanistic insight into how heterodimeric ABC exporters operate. PubMed: 25377891DOI: 10.1038/ncomms6419 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.65 Å) |
Structure validation
Download full validation report
