Poster Presentation The 48th Lorne Conference on Protein Structure and Function 2023

Structural and functional characterisation of AAA+ ATPase p97 protein homologs from malaria parasite (#431)

Mehdi Youssefi Matak 1 2 , George Kobakhidze 1 3 , Hamish G. Brown 4 , Sepideh Valimehr 1 2 4 , Mohsen Kazemi 1 2 , Ashish Sethi 1 5 , Isabelle Rouiller 1 2
  1. Biochemistry & Pharmacology, The University of Melbourne, Melbourne, VIC, Australia
  2. ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Melbourne, VIC, Australia
  3. Max Perutz Labs, Vienna Biocenter, Center for Medical Biochemistry, Medical University of Vienna, Vienna, Australia
  4. Ian Holmes Imaging Centre, Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Melbourne, VIC, Australia
  5. Australian Nuclear Science Technology Organisation, The Australian Synchrotron, Melbourne, VIC, Australia

Malaria threatens millions of people and has caused over 400 thousand deaths in 2020 alone. The emergence of malaria strains resistant to treatments demands new targets. The AAA+ ATPase enzyme p97 (aka VCP or CDC48), is a multimeric machine that acts by segregating and unfolding improperly folded proteins from larger complexes at the expense of ATP molecules. This is followed by the action of the proteasome in the ubiquitin-proteasome pathway leading to the target protein components getting recycled in the cells. Two homologues of p97 in P. falciparum have previously been identified in the parasite. One localises in the cytoplasm (Pf-2) and likely carries out diverse tasks previously observed in other species and a second homolog in the parasite’s apicoplast (Pf-1) with less known cellular functions. Structural characterisation of these two proteins (with not high homology to human p97) can inform our strategies in designing more effective and specific inhibitory targets against the malaria parasite cells. Recombinant Pf-1 and Pf-2 proteins were expressed in E. coli and purified. Cryo-electron microscopy (cryo-EM) workflow was followed to arrive at a 3D reconstruction of the proteins.