PhD Scientific Days 2023

Translational Medicine - Posters O

Metadynamics for ABCG36 Transport Pathway Characterization

Text of the abstract

The pleiotropic plant ABCG transporter, AtABCG36 has a role in the export of a few structurally distinct substrates, including the auxin hormone precursor, indole-3-butyric acid (IBA), and camalexin (CAM), which has been demonstrated to participate in the defense against several pathogens in Arabidopsis. Because of these important functions, we aimed to investigate the ABCG36 substrate recognition and transport mechanisms using molecular dynamics. This transporter consists of two large transmembrane domains (TM) with a central pocket between them. After substrate binding, the two ATP-bound nucleotide-binding domains close, and the substrate is moved from the central binding pocket to the extracellular space through the Leu/Phe-valve. We found in our experiments that the L704F mutation in this valve diminishes CAM transport while retaining IBA transport. This indicates the Leu/Phe-valve participates in substrate selection. Acknowledgements: NKFI-127961, KIFÜ HU HPC, MTA Wigner GPU Laboratory