info:eu-repo/semantics/article
A bacterial 2[4Fe–4S] ferredoxin as redox partner of the plastidic-type ferredoxin-NADP + reductase from Leptospira interrogans
Fecha
2019-04Registro en:
Lopez Rivero, Arleth Susana; Rossi, María Agustina; Ceccarelli, Eduardo Augusto; Catalano Dupuy, Daniela Luján; A bacterial 2[4Fe–4S] ferredoxin as redox partner of the plastidic-type ferredoxin-NADP + reductase from Leptospira interrogans; Elsevier Science; Biochimica et Biophysica Acta - General Subjects; 1863; 4; 4-2019; 651-660
0304-4165
CONICET Digital
CONICET
Autor
Lopez Rivero, Arleth Susana
Rossi, María Agustina
Ceccarelli, Eduardo Augusto
Catalano Dupuy, Daniela Luján
Resumen
Background: Ferredoxins are small iron-sulfur proteins that participate as electron donors in various metabolic pathways. They are recognized substrates of ferredoxin-NADP + reductases (FNR) in redox metabolisms in mitochondria, plastids, and bacteria. We previously found a plastidic-type FNR in Leptospira interrogans (LepFNR), a parasitic bacterium of animals and humans. Nevertheless, we did not identify plant-type ferredoxins or flavodoxins, the common partners of this kind of FNR. Methods: Sequence alignment, phylogenetical analyses and structural modeling were performed for the identification of a 2[4Fe–4S] ferredoxin (LepFd2) as a putative redox partner of LepFNR in L. interrogans. The gene encoding LepFd2 was cloned and the protein overexpressed and purified. The functional properties of LepFd2 and LepFNR-LepFd2 complex were analyzed by kinetic and mutagenesis studies. Results: We succeeded in expressing and purifying LepFd2 with its Fe–S cluster properly bound. We found that LepFd2 exchanges electrons with LepFNR. Moreover, a unique structural subdomain of LepFNR (loop P75-Y91), was shown to be involved in the recognition and binding of LepFd2. This structural subdomain is not found in other FNR homologs. Conclusions: We report for the first time a redox pair in L. interrogans in which a plastidic FNR exchanges electron with a bacterial 2[4Fe–4S] ferredoxin. We characterized this reaction and proposed a model for the productive LepFNR-LepFd2 complex. General significance: Our findings suggest that the interaction of LepFNR with the iron-sulfur protein would be different from the one previously described for the homolog enzymes. This knowledge would be useful for the design of specific LepFNR inhibitors.