A dimeric chlorite dismutase exhibits O2-generating activity and acts as a chlorite antioxidant in Klebsiella pneumoniae MGH 78578.

Chlorite dismutases (Clds) convert chlorite to O2 and Cl(-), stabilizing heme in the presence of strong oxidants and forming the O═O bond with high efficiency. The enzyme from the pathogen Klebsiella pneumoniae (KpCld) represents a subfamily of Clds that share most of their active site structure with efficient O2-producing Clds, even though they have a truncated monomeric structure, exist as a dimer rather than a pentamer, and come from Gram-negative bacteria without a known need to degrade chlorite. We hypothesized that KpCld, like others in its subfamily, should be able to make O2 and may serve an in vivo antioxidant function.

The chlorite dismutase (HemQ) from Staphylococcus aureus has a redox-sensitive heme and is associated with the small colony variant phenotype.

The chlorite dismutases (C-family proteins) are a widespread family of heme-binding proteins for which chemical and biological roles remain unclear. An association of the gene with heme biosynthesis in Gram-positive bacteria was previously demonstrated by experiments involving introduction of genes from two Gram-positive species into heme biosynthesis mutant strains of Escherichia coli, leading to the gene being renamed hemQ. To assess the gene product's biological role more directly, a Staphylococcus aureus strain with an inactivated hemQ gene was generated and shown to be a slow growing small colony variant under aerobic but not anaerobic conditions.

Chlorite dismutases, DyPs, and EfeB: 3 microbial heme enzyme families comprise the CDE structural superfamily.

Heme proteins are extremely diverse, widespread, and versatile biocatalysts, sensors, and molecular transporters. The chlorite dismutase family of hemoproteins received its name due to the ability of the first-isolated members to detoxify anthropogenic ClO(2)(-), a function believed to have evolved only in the last few decades. Family members have since been found in 15 bacterial and archaeal genera, suggesting ancient roots.