An integrated transport mechanism of the maltose ABC importer
An integrated transport mechanism of the maltose ABC importer
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DOI：
10.1016/j.resmic.2019.09.004
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发表时间：
2019-11-01
影响因子：
2.6
通讯作者：
Orelle, Cedric
中科院分区：
文献类型：
--
作者：
Maechtel, Rebecca;Narducci, Alessandra;Orelle, Cedric
ATP 结合盒 (ABC) 转运蛋白利用 ATP 水解的能量主动跨生物膜转运多种分子。生物化学、生物物理和结构研究相结合，已将麦芽糖转运蛋白 MalFGK(2) 确定为 ABC 家族中特征最明确的蛋白质之一。 MaIF 和 MaIG 是跨膜结构域，两个 MalK 形成核苷酸结合结构域的同二聚体。周质麦芽糖结合蛋白 (MalE) 将麦芽糖和其他麦芽糖糊精递送至转运蛋白，并触发其 ATP 酶活性。底物输入通过 MaIK(2) 中 ATP 驱动的构象变化以单向方式发生，从而允许 MaIF 中的底物结合位点交替进入膜的每一侧。在这篇综述中，我们考虑了所有当前可用的信息，提出了运输过程的综合分子机制。此外，我们总结了剩余的不一致之处，并概述了未来可能的路线，以破译 MaIEFGK(2) 综合体和相关进口商系统运输的完整机械细节。 (C) 2019 年作者。由 Elsevier Masson SAS 代表巴斯德研究所出版。
ATP-binding cassette (ABC) transporters use the energy of ATP hydrolysis to transport a large diversity of molecules actively across biological membranes. A combination of biochemical, biophysical, and structural studies has established the maltose transporter MalFGK(2) as one of the best characterized proteins of the ABC family. MaIF and MaIG are the transmembrane domains, and two MalKs form a homodimer of nucleotide-binding domains. A periplasmic maltose-binding protein (MalE) delivers maltose and other maltodextrins to the transporter, and triggers its ATPase activity. Substrate import occurs in a unidirectional manner by ATP-driven conformational changes in MaIK(2) that allow alternating access of the substrate-binding site in MaIF to each side of the membrane. In this review, we present an integrated molecular mechanism of the transport process considering all currently available information. Furthermore, we summarize remaining inconsistencies and outline possible future routes to decipher the full mechanistic details of transport by MaIEFGK(2) complex and that of related importer systems. (C) 2019 The Authors. Published by Elsevier Masson SAS on behalf of Institut Pasteur.