Crystal Structures of T. b. rhodesiense Adenosine Kinase Complexed with Inhibitor and Activator: Implications for Catalysis and Hyperactivation
Abstract
Background
The essential purine salvage pathway of Trypanosoma brucei bears interesting catalytic enzymes for chemotherapeutic intervention of Human African Trypanosomiasis. Unlike mammalian cells, trypanosomes lack de novo purine synthesis and completely rely on salvage from their hosts. One of the key enzymes is adenosine kinase which catalyzes the phosphorylation of ingested adenosine to form adenosine monophosphate (AMP) utilizing adenosine triphosphate (ATP) as the preferred phosphoryl donor.
Methods and Findings
Here, we present the first structures of Trypanosoma brucei rhodesiense adenosine kinase (TbrAK): the structure of TbrAK in complex with the bisubstrate inhibitor P1,P5-di(adenosine-5′)-pentaphosphate (AP5A) at 1.55 Å, and TbrAK complexed with the recently discovered activator 4-[5-(4-phenoxyphenyl)-2H-pyrazol-3-yl]morpholine (compound 1) at 2.8 Å resolution.
Conclusions
The structural details and their comparison give new insights into substrate and activator binding to TbrAK at the molecular level. Further structure-activity relationship analyses of a series of derivatives of compound 1 support the observed binding mode of the activator and provide a possible mechanism of action with respect to their activating effect towards TbrAK. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000037657Publication status
publishedExternal links
Journal / series
PLoS Neglected Tropical DiseasesVolume
Pages / Article No.
Publisher
PLOSOrganisational unit
03782 - Riek, Roland / Riek, Roland
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