Crystal structure of the cofactor‐free form of thioredoxin reductase from Acinetobacter baumannii

Abstract

Thioredoxin reductase (TrxR) is a central component in the thioredoxin system by involving in catalyzing the reduction of thioredoxin, which is critical for organism survival. Because this system is essential, it is a promising target for novel antimicrobial agents. Herein, we solved the 1.9 Å high‐resolution structure of TrxR from Acinetobacter baumannii Thioredoxin reductase (AbTrxR), which is a Gram‐negative, pathogenic bacterium and a drug‐resistant superbug. AbTrxR was cofactor‐free and formed a dimer in solution. AbTrxR contained a longer dimerization loop2 and a shorter β7‐β8 connecting loop than other TrxRs. AbTrxR cofactor‐free form exhibited a flavin‐oxidizing (FO) conformation, whose NADPH domain was located close to the dimeric interface. This structural information might be helpful for development of new antibiotic agents targeting superbugs.