4YMX

Crystal structure of the substrate binding protein of an amino acid ABC transporter

4YMX の概要

• エントリーDOI: 10.2210/pdb4ymx/pdb
• 関連するPDBエントリー: 4YMS 4YMT 4YMU 4YMV 4YMW
• 分子名称: ABC-type amino acid transport system, periplasmic component, ARGININE (3 entities in total)
• 機能のキーワード: abc transporter, two binding sites, substrate specificity, membrane protein complex, transport protein
• 由来する生物種: Caldanaerobacter subterraneus subsp. tengcongensis MB4
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 58127.42

構造登録者

Ge, J.,Yu, J.,Yang, M. (登録日: 2015-03-07, 公開日: 2015-04-22, 最終更新日: 2023-11-08)

主引用文献

Yu, J.,Ge, J.,Heuveling, J.,Schneider, E.,Yang, M.
Structural basis for substrate specificity of an amino acid ABC transporter
Proc.Natl.Acad.Sci.USA, 112:5243-5248, 2015

PubMed Abstract: ATP-binding cassette (ABC) transporters are ubiquitous integral membrane proteins that translocate a variety of substrates, ranging from ions to macromolecules, either out of or into the cytosol (hence defined as importers or exporters, respectively). It has been demonstrated that ABC exporters and importers function through a common mechanism involving conformational switches between inward-facing and outward-facing states; however, the mechanism underlying their functions, particularly substrate recognition, remains elusive. Here we report the structures of an amino acid ABC importer Art(QN)2 from Thermoanaerobacter tengcongensis composed of homodimers each of the transmembrane domain ArtQ and the nucleotide-binding domain ArtN, either in its apo form or in complex with substrates (Arg, His) and/or ATPs. The structures reveal that the straddling of the TMDs around the twofold axis forms a substrate translocation pathway across the membrane. Interestingly, each TMD has a negatively charged pocket that together create a negatively charged internal tunnel allowing amino acids carrying positively charged groups to pass through. Our structural and functional studies provide a better understanding of how ABC transporters select and translocate their substrates.

PubMed: 25848002
DOI: 10.1073/pnas.1415037112

実験手法

X-RAY DIFFRACTION (1.481 Å)