Identification of an Alternating-Access Dynamics Mutant of EmrE with Impaired Transport.

ABSTRACT: Proteins that perform active transport must alternate the access of a binding site, first to one side of a membrane and then to the other, resulting in the transport of bound substrates across the membrane. To better understand this process, we sought to identify mutants of the small multidrug resistance transporter EmrE with reduced rates of alternating access. We performed extensive scanning mutagenesis by changing every amino acid residue to Val, Ala, or Gly, and then screening the drug resistance phenotypes of the resulting mutants. We identified EmrE mutants that had impaired transport activity but retained the ability to bind substrate and further tested their alternating access rates using NMR. Ultimately, we were able to identify a single mutation, S64V, which significantly reduced

SUBMITTER: Wu C 

PROVIDER: S-EPMC6599891 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature