Palavecino A, Sartorio MG, Carrillo N, Cortez N, Bortolotti A. The extremophilic Andean isolate Acinetobacter sp. Ver3 expresses two ferredoxin-NADP
+ reductase isoforms with different catalytic properties.
FEBS Lett 2024;
598:670-683. [PMID:
38433717 DOI:
10.1002/1873-3468.14826]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 01/04/2024] [Accepted: 01/06/2024] [Indexed: 03/05/2024]
Abstract
Ferredoxin/flavodoxin-NADPH reductases (FPRs) catalyze the reversible electron transfer between NADPH and ferredoxin/flavodoxin. The Acinetobacter sp. Ver3 isolated from high-altitude Andean lakes contains two isoenzymes, FPR1ver3 and FPR2ver3. Absorption spectra of these FPRs revealed typical features of flavoproteins, consistent with the use of FAD as a prosthetic group. Spectral differences indicate distinct electronic arrangements for the flavin in each enzyme. Steady-state kinetic measurements show that the enzymes display catalytic efficiencies in the order of 1-6 μm-1·s-1, although FPR1ver3 exhibited higher kcat values compared to FPR2ver3. When flavodoxinver3 was used as a substrate, both reductases exhibited dissimilar behavior. Moreover, only FPR1ver3 is induced by oxidative stimuli, indicating that the polyextremophile Ver3 has evolved diverse strategies to cope with oxidative environments.
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