7WIW

Cryo-EM structure of Mycobacterium tuberculosis irtAB complexed with ATP in an occluded conformation

7WIW の概要

• エントリーDOI: 10.2210/pdb7wiw/pdb
• EMDBエントリー: 32538
• 分子名称: Mycobactin import ATP-binding/permease protein IrtB, Mycobactin import ATP-binding/permease protein IrtA, ADENOSINE-5'-TRIPHOSPHATE, ... (4 entities in total)
• 機能のキーワード: irtab, abc exporter-liker importer, iron-loaded siderophore, mycobacterium tuberculosis, membrane protein
• 由来する生物種: Mycobacterium tuberculosis H37Rv; 詳細
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 155166.09

構造登録者

Zhang, B.,Sun, S.,Yang, H.,Rao, Z. (登録日: 2022-01-05, 公開日: 2023-01-25, 最終更新日: 2024-04-10)

主引用文献

Sun, S.,Gao, Y.,Yang, X.,Yang, X.,Hu, T.,Liang, J.,Xiong, Z.,Ran, Y.,Ren, P.,Bai, F.,Guddat, L.W.,Yang, H.,Rao, Z.,Zhang, B.
Cryo-EM structures for the Mycobacterium tuberculosis iron-loaded siderophore transporter IrtAB.
Protein Cell, 14:448-458, 2023

PubMed Abstract: The adenosine 5'-triphosphate (ATP)-binding cassette (ABC) transporter, IrtAB, plays a vital role in the replication and viability of Mycobacterium tuberculosis (Mtb), where its function is to import iron-loaded siderophores. Unusually, it adopts the canonical type IV exporter fold. Herein, we report the structure of unliganded Mtb IrtAB and its structure in complex with ATP, ADP, or ATP analogue (AMP-PNP) at resolutions ranging from 2.8 to 3.5 Å. The structure of IrtAB bound ATP-Mg2+ shows a "head-to-tail" dimer of nucleotide-binding domains (NBDs), a closed amphipathic cavity within the transmembrane domains (TMDs), and a metal ion liganded to three histidine residues of IrtA in the cavity. Cryo-electron microscopy (Cryo-EM) structures and ATP hydrolysis assays show that the NBD of IrtA has a higher affinity for nucleotides and increased ATPase activity compared with IrtB. Moreover, the metal ion located in the TM region of IrtA is critical for the stabilization of the conformation of IrtAB during the transport cycle. This study provides a structural basis to explain the ATP-driven conformational changes that occur in IrtAB.

PubMed: 36882106
DOI: 10.1093/procel/pwac060

実験手法

ELECTRON MICROSCOPY (3.12 Å)