000164168 001__ 164168
000164168 005__ 20251127172930.0
000164168 0247_ $$2doi$$a10.1016/j.ijbiomac.2025.148860
000164168 0248_ $$2sideral$$a146338
000164168 037__ $$aART-2025-146338
000164168 041__ $$aeng
000164168 100__ $$0(orcid)0000-0001-7947-8813$$aMinjarez-Saenz, Martha
000164168 245__ $$aA π-stacking gate for redox control in flavin ferredoxin-thioredoxin reductases
000164168 260__ $$c2025
000164168 5060_ $$aAccess copy available to the general public$$fUnrestricted
000164168 5203_ $$aFlavin ferredoxin-thioredoxin reductases (FFTRs) constitute a unique class of enzymes that transfer electrons from low-potential ferredoxins (Fdxs) to thioredoxins (Trxs) through a flavin cofactor. They are widely distributed across bacterial lineages, including cyanobacteria and anaerobes such as Clostridium, where they function either as the sole Trx reductase or in parallel with canonical NADPH-dependent or iron–sulfur systems. A distinguishing feature of cyanobacterial FFTRs is a C-terminal tail containing a conserved tryptophan (Trp) that engages in a π-stacking interaction with the flavin—a motif absent in clostridial orthologs. In this study, we use the cyanobacterial FFTR from Gloeobacter violaceus as a model to demonstrate that the C-terminal tail and its conserved aromatic residue modulate the FAD electronic environment, electron transfer efficiency, and Fdx donor interactions. Mutants lacking the tail or Trp exhibited increased flavin solvent exposure, a redox potential shift of over 200 mV toward less negative values, altered reduction kinetics, impaired electron flow to the redox-active disulfide, and reduced specificity for Fdx binding. These results reveal a dual role for the C-terminal tail: it establishes a productive donor-binding interface and shapes the FAD environment to meet the thermodynamic and kinetic requirements for efficient intramolecular electron transfer to the redox-active disulfide. Collectively, these findings provide mechanistic insight into how peripheral structural features, such as FAD-aromatic π-stacking interactions, govern flavin reactivity, donor specificity, and redox behavior in cyanobacterial FFTRs, underscoring their relevance and offering a framework for engineering redox-active biocatalysts for synthetic biology and metabolic applications
000164168 536__ $$9info:eu-repo/grantAgreement/ES/AEI/PID2023-150714OB-I00$$9info:eu-repo/grantAgreement/ES/DGA/E35-23R$$9info:eu-repo/grantAgreement/ES/MICINN-AEI/PID2019-110900GB-I00$$9info:eu-repo/grantAgreement/ES/MICINN/PID2022-136369NB-I00
000164168 540__ $$9info:eu-repo/semantics/openAccess$$aby-nc$$uhttps://creativecommons.org/licenses/by-nc/4.0/deed.es
000164168 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion
000164168 700__ $$aCorrea-Pérez, Víctor$$uUniversidad de Zaragoza
000164168 700__ $$aRivero, Maria Isabel$$uUniversidad de Zaragoza
000164168 700__ $$aSadeghi, Sheila J.
000164168 700__ $$aCalvo, Javier
000164168 700__ $$0(orcid)0000-0001-5702-4538$$aVelázquez-Campoy, Adrián$$uUniversidad de Zaragoza
000164168 700__ $$aGago, Federico
000164168 700__ $$aBuey, Rubén M.
000164168 700__ $$aMartínez-Júlvez, Marta
000164168 700__ $$0(orcid)0000-0001-8743-0182$$aMedina, Milagros$$uUniversidad de Zaragoza
000164168 700__ $$aBalsera, Monica
000164168 7102_ $$11002$$2060$$aUniversidad de Zaragoza$$bDpto. Bioq.Biolog.Mol. Celular$$cÁrea Bioquímica y Biolog.Mole.
000164168 773__ $$g333 (2025), 148860 [11 pp.]$$pInt. j. biol. macromol.$$tInternational journal of biological macromolecules$$x0141-8130
000164168 8564_ $$s2112644$$uhttps://zaguan.unizar.es/record/164168/files/texto_completo.pdf$$yVersión publicada
000164168 8564_ $$s2462990$$uhttps://zaguan.unizar.es/record/164168/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada
000164168 909CO $$ooai:zaguan.unizar.es:164168$$particulos$$pdriver
000164168 951__ $$a2025-11-27-15:16:21
000164168 980__ $$aARTICLE