RESUMO

Here, we present the characterization of a trypanosomatid nucleoside diphosphate kinase (TcNDPK1) exhibiting nuclease activity. This is the first identification of a NDPK with this property in trypanosomatid organisms. The recombinant TcNDPK1 protein cleaves not only linear DNA, but also supercoiled plasmid DNA. Additionally, TcNDPK1 is capable of degrading Trypanosoma cruzi genomic DNA. ATP or ADP did not affect the nuclease activity, while the absence of Mg2+ completely inhibits this activity. NDPK and nuclease activities were inhibited at the same temperature, suggesting the presence of related catalytic sites. Furthermore, phenogram analysis showed that TcNDPK1 is close to Drosophila melanogaster and human NDPKs. The unspecific nuclease activity could suggest a participation in cellular processes such as programmed cell death.

Assuntos

Núcleosídeo-Difosfato Quinase/metabolismo , Trypanosoma cruzi/enzimologia , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Sequência de Aminoácidos , Animais , Sequência Conservada , DNA de Protozoário/metabolismo , DNA Super-Helicoidal/metabolismo , Temperatura Alta , Magnésio/metabolismo , Núcleosídeo-Difosfato Quinase/química , Núcleosídeo-Difosfato Quinase/genética , Filogenia , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Fatores de Tempo , Trypanosoma cruzi/classificação , Trypanosoma cruzi/genética