Mutations of charged amino acids at the cytoplasmic end of transmembrane helix 2 affect transport activity of the budding yeast multidrug resistance protein Pdr5p.

ABSTRACT: Pdr5p is a major ATP-binding cassette (ABC) transporter in Saccharomyces cerevisiae. It displays a sequence and functional homology to the pathogenic Candida albicans multidrug resistance protein Cdr1p. The transmembrane helices of Pdr5p act in substrate recognition, binding, translocation and eventual removal of toxic substances out of the plasma membrane via the formation of a binding pocket. In this study, we identify two novel Pdr5 mutants (E574K and E580K), which exhibit impaired substrate efflux functions. Both mutants remained hypersensitive to all tested Pdr5p substrates without affecting their protein expression levels, localization or ATPase activities. As E574 and E580 are both located adjacent to the predicted cytoplasmic end of transmembrane helix 2, this implies that such cha

SUBMITTER: Dou W 

PROVIDER: S-EPMC5815066 | biostudies-literature | 2016 Jun

REPOSITORIES: biostudies-literature