4K8O

CRYSTAL STRUCTURE OF THE ATPASE DOMAIN OF TAP1 WITH ATP (D645N, D651A MUTANT)

4K8O の概要

• エントリーDOI: 10.2210/pdb4k8o/pdb
• 分子名称: Antigen peptide transporter 1, ADENOSINE-5'-TRIPHOSPHATE, NICKEL (II) ION, ... (6 entities in total)
• 機能のキーワード: nucleotide binding domain, peptide transport, transport protein
• 由来する生物種: Rattus norvegicus (brown rat,rat,rats)
• 細胞内の位置: Endoplasmic reticulum membrane; Multi-pass membrane protein: P36370
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 30220.74

構造登録者

Vakkasoglu, A.S.,Grossmann, N.,Hulpke, S.,Abele, R.,Tampe, R.,Gaudet, R. (登録日: 2013-04-18, 公開日: 2014-09-03, 最終更新日: 2024-11-06)

主引用文献

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

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: 25377891
DOI: 10.1038/ncomms6419

実験手法

X-RAY DIFFRACTION (2.65 Å)