3B5Y

Crystal Structure of MsbA from Salmonella typhimurium with AMPPNP

3B5Y の概要

• エントリーDOI: 10.2210/pdb3b5y/pdb
• 関連するPDBエントリー: 3B5W 3B5X 3B5Z 3B60
• 分子名称: Lipid A export ATP-binding/permease protein msbA, PHOSPHOAMINOPHOSPHONIC ACID-ADENYLATE ESTER (2 entities in total)
• 機能のキーワード: abc transporter, msba, lipid flippase, atp-binding, hydrolase, inner membrane, lipid transport, membrane, nucleotide-binding, transmembrane, membrane protein
• 由来する生物種: Salmonella typhimurium
• 細胞内の位置: Cell inner membrane; Multi-pass membrane protein (By similarity): P63359
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 259658.68

構造登録者

Ward, A.,Reyes, C.L.,Yu, J.,Roth, C.B.,Chang, G. (登録日: 2007-10-26, 公開日: 2007-12-04, 最終更新日: 2024-02-21)

主引用文献

Ward, A.,Reyes, C.L.,Yu, J.,Roth, C.B.,Chang, G.
Flexibility in the ABC transporter MsbA: Alternating access with a twist.
Proc.Natl.Acad.Sci.Usa, 104:19005-19010, 2007

PubMed Abstract: ATP-binding cassette (ABC) transporters are integral membrane proteins that translocate a wide variety of substrates across cellular membranes and are conserved from bacteria to humans. Here we compare four x-ray structures of the bacterial ABC lipid flippase, MsbA, trapped in different conformations, two nucleotide-bound structures and two in the absence of nucleotide. Comparison of the nucleotide-free conformations of MsbA reveals a flexible hinge formed by extracellular loops 2 and 3. This hinge allows the nucleotide-binding domains to disassociate while the ATP-binding half sites remain facing each other. The binding of the nucleotide causes a packing rearrangement of the transmembrane helices and changes the accessibility of the transporter from cytoplasmic (inward) facing to extracellular (outward) facing. The inward and outward openings are mediated by two different sets of transmembrane helix interactions. Altogether, the conformational changes between these structures suggest that large ranges of motion may be required for substrate transport.

PubMed: 18024585
DOI: 10.1073/pnas.0709388104

実験手法

X-RAY DIFFRACTION (4.5 Å)