Download MendeleyCrystal Structure of the Anopheles Gambiae 3-Hydroxykynurenine Transaminase
Rossi, F., Garavaglia, S., Giovenzana, G.B., Arca, B., Li, J., Rizzi, M.(2006) Proc Natl Acad Sci U S A 103: 5711
- PubMed: 16585514
- DOI: https://doi.org/10.1073/pnas.0510233103
- Primary Citation of Related Structures:
2CH1, 2CH2 - PubMed Abstract:
In Anopheles gambiae, the vector for the most deadly malaria parasite Plasmodium falciparum, xanthurenic acid (XA) plays a key role in parasite gametogenesis and fertility. In mosquitoes, XA is produced by transamination of 3-hydroxykynurenine (3-HK), a reaction that represents the main route to prevent the accumulation of the potentially toxic 3-HK excess. Interfering with XA metabolism in A. gambiae therefore appears an attractive avenue for the development of malaria transmission-blocking drugs and insecticides. We have determined the crystal structure of A. gambiae 3-HK transaminase in its pyridoxal 5'-phosphate form and in complex with a newly synthesized competitive enzyme inhibitor. Structural inspection of the enzyme active site reveals the key molecular determinants for ligand recognition and catalysis. Major contributions toward inhibitor binding are provided by a salt bridge between the inhibitor carboxylate and Arg-356 and by a remarkable hydrogen bond network involving the anthranilic moiety of the inhibitor and backbone atoms of residues Gly-25 and Asn-44. This study may be useful for the structure-based design of specific enzyme inhibitors of potential interest as antimalarial agents.
Organizational Affiliation:
Dipartimento di Scienze Chimiche, Alimentari Farmaceutiche e Farmacologiche-Drug and Food Biotechnology Center, University of Piemonte Orientale "Amedeo Avogadro," Via Bovio 6, 28100 Novara, Italy.
