Trypanosoma brucei S-adenosylmethionine decarboxylase N terminus is essential for allosteric activation by the regulatory subunit prozyme

Background: Trypanosoma brucei S-adenosylmethionine decarboxylase (AdoMetDC) is activated by heterodimerization with a catalytically dead paralog, prozyme. Results: Trypanosomatid-specific residues in the AdoMetDC N terminus are essential for prozyme-mediated activation but not for heterodimerization. Conclusion: AdoMetDC activation likely involves a conformational change of the N-terminal peptide. Significance: Development of conformationally sensitive AdoMetDC inhibitors may provide a species-selective mechanism to inhibit trypanosomatid AdoMetDCs.