Download MendeleyCryo-EM reveals a phosphorylated R-domain envelops the NBD1 catalytic domain in an ABC transporter.
Souza Amado de Carvalho, R., Rasel, M.S.I., Khandelwal, N.K., Tomasiak, T.M.(2024) Life Sci Alliance 7
- PubMed: 39209537
- DOI: https://doi.org/10.26508/lsa.202402779
- Primary Citation of Related Structures:
9AYC - PubMed Abstract:
Many ATP-binding cassette transporters are regulated by phosphorylation on long and disordered loops which presents a challenge to visualize with structural methods. We have trapped an activated state of the regulatory domain (R-domain) of yeast cadmium factor 1 (Ycf1) by enzymatically enriching the phosphorylated state. A 3.23 Å cryo-EM structure reveals an R-domain structure with four phosphorylated residues and the position for the entire R-domain. The structure reveals key R-domain interactions including a bridging interaction between NBD1 and NBD2 and an interaction with the R-insertion, another regulatory region. We scanned these interactions by systematically replacing segments along the entire R-domain with scrambled combinations of alanine, glycine, and glutamine and probing function under cellular conditions that require the Ycf1 function. We find a close match with these interactions and interacting regions on our R-domain structure that points to the importance of most well-structured segments for function. We propose a model where the R-domain stabilizes a transport-competent state upon phosphorylation by enveloping NBD1 entirely.
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, USA.
Organizational Affiliation:
