167981 20260127151100.0 doi 10.1111/ppl.12621 sideral 104602 ART-2018-104602 eng Koskela, M.M. Arabidopsis FNRL protein is an NADPH-dependent chloroplast oxidoreductase resembling bacterial ferredoxin-NADP+ reductases 2018 Access copy available to the general public Unrestricted Plastidic ferredoxin-NADP+ oxidoreductases (FNRs; EC:1.18.1.2) together with bacterial type FNRs (FPRs) form the plant-type FNR family. Members of this group contain a two-domain scaffold that forms the basis of an extended superfamily of flavin adenine dinucleotide (FAD) dependent oxidoreductases. In this study, we show that the Arabidopsis thaliana At1g15140 [Ferredoxin-NADP+ oxidoreductase-like (FNRL)] is an FAD-containing NADPH dependent oxidoreductase present in the chloroplast stroma. Determination of the kinetic parameters using the DCPIP NADPH-dependent diaphorase assay revealed that the reaction catalysed by a recombinant FNRL protein followed a saturation Michaelis–Menten profile on the NADPH concentration with kcat = 3.2 ± 0.2 s-1, Km NADPH = 1.6 ± 0.3 µM and kcat/Km NADPH = 2.0 ± 0.4 µM-1 s-1. Biochemical assays suggested that FNRL is not likely to interact with Arabidopsis ferredoxin 1, which is supported by the sequence analysis implying that the known Fd-binding residues in plastidic FNRs differ from those of FNRL. In addition, based on structural modelling FNRL has an FAD-binding N-terminal domain built from a six-stranded ß-sheet and one a-helix, and a C-terminal NADP+-binding a/ß domain with a five-stranded ß-sheet with a pair of a-helices on each side. The FAD-binding site is highly hydrophobic and predicted to bind FAD in a bent conformation typically seen in bacterial FPRs. info:eu-repo/grantAgreement/ES/DGA/B18 info:eu-repo/grantAgreement/ES/MINECO/BIO2016-75183-P info:eu-repo/semantics/openAccess All rights reserved http://www.europeana.eu/rights/rr-f/ 3.0 2018 PLANT SCIENCES 48 / 226 = 0.212 2018 Q1 T1 1.23 2018 Cell Biology 2018 Q1 Genetics 2018 Q1 Plant Science 2018 Q1 Physiology 2018 Q1 Medicine (miscellaneous) 2018 Q1 info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion Dahlström, K.M. Goñi, G. (orcid)0000-0003-4010-849X Lehtimäki, N. Nurmi, M. Velazquez-Campoy, A. Universidad de Zaragoza (orcid)0000-0001-5702-4538 Hanke, G. Bölter, B. Salminen, T.A. Medina, M. Universidad de Zaragoza (orcid)0000-0001-8743-0182 Mulo, P. 1002 060 Universidad de Zaragoza Dpto. Bioq.Biolog.Mol. Celular Área Bioquímica y Biolog.Mole. 162, 2 (2018), 177-190 Physiol. Plant. PHYSIOLOGIA PLANTARUM 0031-9317 386764 http://zaguan.unizar.es/record/167981/files/texto_completo.pdf Postprint 1075562 http://zaguan.unizar.es/record/167981/files/texto_completo.jpg?subformat=icon icon Postprint oai:zaguan.unizar.es:167981 articulos driver 2026-01-27-15:07:19 ARTICLE