Mol Biochem Parasitol. 2014 Apr 11. pii: S0166-6851(14)00041-3. doi: 10.1016/j.molbiopara.2014.04.002. [Epub ahead of print]

Isolation and molecular characterization of the shikimate dehydrogenase domain from the Toxoplasma gondii AROM complex

Peek J¹, Castiglione G¹, Shi T¹, Christendat D².

Abstract

The apicomplexan parasite Toxoplasma gondii, the etiologic agent of toxoplasmosis, is estimated to infect 10-80% of different human populations. T. gondii encodes a large pentafunctional polypeptide known as the AROM complex which catalyzes five reactions in the shikimate pathway, a metabolic pathway required for the biosynthesis of the aromatic amino acids and a promising target for anti-parasitic agents. Here, we present the isolation, cloning and kinetic characterization of the shikimate dehydrogenase domain (TgSDH) from the T. gondii AROM complex. Recombinant TgSDH catalyzed the NADP⁺-dependent oxidation of shikimate in the absence of the remaining AROM domains and was sensitive to inhibition by a previously identified SDH inhibitor. Analysis of the TgSDH amino acid sequence revealed a number of novel insertions not found in SDH homologs from other organisms. Nevertheless, a three-dimensional structural model of TgSDH predicts a high level of conservation in the 'core' structure of the enzyme.
Copyright © 2014. Published by Elsevier B.V.

KEYWORDS:

AROM complex, Enzyme inhibition, Enzyme kinetics, Shikimate dehydrogenase, Toxoplasma gondii, shikimate pathway

PMID:

24731949

[PubMed - as supplied by publisher]