Tripartite transporters as mechanotransmitters in periplasmic alternating-access mechanisms

FEBS Letters

article

Satoshi Murakami¹  Ui Okada¹  Hendrik W. van Veen² 

[1] Department of Life Science and Technology, Tokyo Institute of Technology;Department of Pharmacology, University of Cambridge

关键词: ABC transporters;    cryo-EM;    drug efflux transporters;    Gramnegative bacteria;    membrane proteins;    RND transporters;    structural biology;    tripartite transporters;    X-ray crystallography;   

DOI  :  10.1002/1873-3468.13929

来源: John Wiley & Sons Ltd.

【 摘 要 】

To remove xenobiotics from the periplasmic space, Gram-negative bacteria utilise unique tripartite efflux systems in which a molecular engine in the plasma membrane connects to periplasmic and outer membrane subunits. Substrates bind to periplasmic sections of the engine or sometimes to the periplasmic subunits. Then, the tripartite machines undergo conformational changes that allow the movement of the substrates down the substrate translocation pathway to the outside of the cell. The transmembrane (TM) domains of the tripartite resistance-nodulation-drug-resistance (RND) transporters drive these conformational changes by converting proton motive force into mechanical motion. Similarly, the TM domains of tripartite ATP-binding cassette (ABC) transporters transmit mechanical movement associated with nucleotide binding and hydrolysis at the nucleotide-binding domains to the relevant subunits in the periplasm. In this way, metabolic energy is coupled to periplasmic alternating-access mechanisms to achieve substrate transport across the outer membrane.

【 授权许可】

Unknown