Work

Functional recoding of Chlamydomonas reinhardtii thioredoxin type-h into photosynthetic type-f by switching selectivity determinants

Year: 2025

Type: article

Abstract: Thioredoxins are ubiquitous disulfide reductases folded as an α/β domain of 100-120 amino acid residues. Functional redox site is composed of a pair of cysteines in a canonical WCGPC pentapeptide exposed at the surface of thioredoxins, that reduces disulfide bonds on target proteins. Several genetic isoforms of thioredoxins are phylogenetically classified into seven types, including type-h involved in general functions in the cytosol and type-f specifically associated to photosynthetic functions in chloroplasts. Specialization of thioredoxin function is correlated to its selectivity towards a type-dependent repertoire of protein targets. In this study, we combined biochemical and computational approaches to identify amino acid residues of photosynthetic type-f thioredoxin contributing to target the Calvin-Benson-Bassham cycle enzymes fructose-1,6-bisphosphatase and sedoheptulose-1,7-bisphosphatase. By introducing these residues into the scaffold of type-h thioredoxin, we generated a synthetic chimera of thioredoxin-h active towards photosynthetic fructose-1,6-bisphosphatase in vitro . Our combined computational and experimental approach provides a general pipeline for the design of molecular switches, enabling precise functional control.

Source: Frontiers in Plant Science

DOI: 10.3389/fpls.2025.1554272

Authors: Stéphane D. Lemaire, Gianluca Lombardi, Andrea Mancini, Alessandra Carbone, Julien Henri

Institutions: Centre National de la Recherche Scientifique, Sorbonne Université, Biologie Computationnelle, Quantitative et Synthétique, Institut Universitaire de France

Language: English

Topic: Redox biology and oxidative stress

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: gold

Estimated APC paid: $3,801

Funder: Agence Nationale de la Recherche