Bacterial enzyme with active thiol group

Bacterial enzymes with active thiol groups are a heterogeneous group of proteins characterized by the presence of reactive cysteine residues in their active sites, which typically function as redox sensors, catalysts, or structural elements[1][2][3]. These enzymes play critical roles in cellular redox regulation, protection against oxidative stress, and key metabolic pathways such as glycolysis (e.g., glyceraldehyde-3-phosphate dehydrogenase, GAPDH), disulfide bond formation and isomerization (e.g., thiol oxidoreductases of the Dsb family), and sulfur amino acid metabolism (e.g., cysteine-thiol lyases)[2][3][4][5]. In bacteria, the maintenance of these thiol groups in a reduced state often relies on low molecular weight thiols such as glutathione (in Gram-negative bacteria), mycothiol (in Actinomycetes), and bacillithiol (in Firmicutes), which protect enzymes from oxidative inactivation and modulate reversible modifications such as S-thiolation[1][2]. Many of these enzymes are essential for bacterial viability and adaptation under stress, thus representing potential antibacterial drug targets, though this is not a single molecular entity but rather a mechanistic class—which renders the entry non-specific and thus problematic as a unique "target"[2][5]. A major therapeutic strategy involves compounds that covalently modify active thiol groups, such as silver ions from nanoparticles, which can directly bind to and inactivate these enzymes, but specificity and host toxicity remain concerns[5]. This entry is too broad/vague to map to one unique, canonical molecular target, but encompasses an important class of bacterial enzymes involved in redox balance, stress resistance, and metabolism.

Other names

Protein thiol oxidoreductasesBacterial thiol-enzymesBacterial redox-active enzymesBacterial cysteine-containing enzymes

Covalent modification of active site thiols (e.g., by metal ions or redox active agents); Inhibition of enzyme function through thiol oxidation or alkylation; Disruption of redox homeostasis