PT  - JOURNAL ARTICLE
AU  - Nitesh Kumar Khandelwal
AU  - Cinthia R. Millan
AU  - Samantha I. Zangari
AU  - Samantha Avila
AU  - Dewight Williams
AU  - Tarjani M. Thaker
AU  - Thomas M. Tomasiak
TI  - The structural basis for regulation of the glutathione transporter Ycf1 by regulatory domain phosphorylation
AID  - 10.1101/2021.06.18.449046
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.06.18.449046
4099  - http://biorxiv.org/content/early/2021/06/20/2021.06.18.449046.short
4100  - http://biorxiv.org/content/early/2021/06/20/2021.06.18.449046.full
AB  - Yeast Cadmium Factor-1 (Ycf1) sequesters heavy metals and glutathione into the vacuole to counter cell stress. Ycf1 belongs to the ATP binding cassette C-subfamily (ABCC) of transporters, many of which are regulated by phosphorylation on intrinsically disordered domains. The regulatory mechanism of phosphorylation is still poorly understood. Here, we report two cryo-EM structures of Ycf1 at 3.4Å and 4.0Å in distinct inward-facing open conformations capturing a previously unobserved ordered state of the intrinsically disordered regulatory domain (R-domain). R-domain phosphorylation is clearly evident and induces a topology promoting electrostatic and hydrophobic interactions with Nucleotide Binding Domain 1 (NBD1) and the lasso domain. These interactions stay constant between the structures and are related by rigid body movements of the NBD1/R-domain complex. Biochemical data further show R-domain phosphorylation reorganizes the Ycf1 architecture and is required for maximal ATPase activity. Together, we provide long-sought after insights into how R-domains control ABCC transporter activity.Competing Interest StatementThe authors have declared no competing interest.