The extremophilic Andean isolate Acinetobacter sp. Ver3 expresses two ferredoxin-NADP+ reductase isoforms with different catalytic properties

FEBS Lett. 2024 Mar;598(6):670-683. doi: 10.1002/1873-3468.14826. Epub 2024 Mar 4.


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.

Keywords: Acinetobacter sp.; Andean wetlands; Ferredoxin/flavodoxin‐NADP (H) reductases; extremophile isolates; oxidative stress.

MeSH terms

  • Ferredoxin-NADP Reductase / chemistry
  • Ferredoxin-NADP Reductase / metabolism
  • Ferredoxins* / metabolism
  • Flavodoxin* / metabolism
  • Kinetics
  • NADP / metabolism
  • Protein Isoforms


  • Flavodoxin
  • NADP
  • Ferredoxins
  • Ferredoxin-NADP Reductase
  • Protein Isoforms