Characterization and structural studies of the Plasmodium falciparum ubiquitin and Nedd8 hydrolase UCHL3.
Like their human hosts, Plasmodium falciparum parasites rely on the ubiquitin-proteasome system for survival. We previously identified PfUCHL3, a deubiquitinating enzyme, and here we characterize its activity and changes in active site architecture upon binding to ubiquitin. We find strong evidence that PfUCHL3 is essential to parasite survival. The crystal structures of both PfUCHL3 alone and in complex with the ubiquitin-based suicide substrate UbVME suggest a rather rigid active site crossover loop that likely plays a role in restricting the size of ubiquitin adduct substrates. Molecular dynamics simulations of the structures and a model of the PfUCHL3-PfNedd8 complex allowed the identification of shared key interactions of ubiquitin and PfNedd8 with PfUCHL3, explaining the dual specificity of this enzyme. Distinct differences observed in ubiquitin binding between PfUCHL3 and its human counterpart make it likely that the parasitic DUB can be selectively targeted while leaving the human enzyme unaffected.
Artavanis-Tsakonas
Katerina
K
Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142, USA.
Weihofen
Wilhelm A
WA
Antos
John M
JM
Coleman
Bradley I
BI
Comeaux
Christy A
CA
Duraisingh
Manoj T
MT
Gaudet
Rachelle
R
Ploegh
Hidde L
HL
D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D003546:Cysteine Endopeptidases; D006801:Humans; D006867:Hydrolases / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D010963:Plasmodium falciparum / Q000201:enzymology*; D046988:Proteasome Endopeptidase Complex; D011485:Protein Binding; D015800:Protozoan Proteins / Q000737:chemistry*; D025801:Ubiquitin / Q000737:chemistry*; D043222:Ubiquitin Thiolesterase
D015800:Protozoan Proteins; D025801:Ubiquitin; D006867:Hydrolases; C509806:UCHL3 protein, human; D043222:Ubiquitin Thiolesterase; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex