Title
haracterization and Structural Insights into Selective E1-E2 Interactions in the Human and Plasmodium falciparum SUMO Conjugation Systems
Author
Katherine H. Reiter, Anita Ramachandran, Xue Xia, Lauren E. Boucher, Jürgen Bosch, Michael J. Matunis
Year
2015
Journal
The Journal of Biological Chemistry
Abstract
Protein modification by small ubiquitin-related modifiers (SUMOs) is essential and conserved in the malaria parasite, Plasmodium falciparum. We have previously shown that interactions between the SUMO E1-activating and E2-conjugating enzyme in P. falciparum are distinct compared with human, suggesting a potential target for development of parasite-specific inhibitors of SUMOylation. The parasite asexual trophozoite stage is susceptible to iron-induced oxidative stress and is subsequently a target for many of the current anti-malarial drugs. Here, we provide evidence that SUMOylation plays a role in the parasite response to oxidative stress during red blood cell stages, indicative of a protective role seen in other organisms. Using x-ray crystallography, we solved the structure of the human SUMO E1 ubiquitin fold domain in complex with the E2, Ubc9. The interface defined in this structure guided in silicomodeling, mutagenesis, and in vitro biochemical studies of the P. falciparum SUMO E1 and E2 enzymes, resulting in the identification of surface residues that explain species-specific interactions. Our findings suggest that parasite-specific inhibitors of SUMOylation could be developed and used in combination therapies with drugs that induce oxidative stress.
Full Article
Instrument
J-810
Keywords
Circular dichroism, Secondary structure, Biochemistry