sodC2

sodC2 is a gene found in some bacteria that encodes a periplasmic copper-zinc superoxide dismutase (CuZnSOD). In species with multiple sodC paralogs, sodC2 is distinguished from a primary copy (often called sodC1) and may differ in regulation or enzyme characteristics. The gene typically includes an N-terminal signal peptide that directs the protein to the Sec-dependent pathway for export into the periplasm, where the mature enzyme resides.

The encoded enzyme detoxifies reactive oxygen species by catalyzing the dismutation of superoxide radicals into hydrogen peroxide and oxygen. This periplasmic localization positions the enzyme to neutralize extracellular or periplasmic superoxide produced by host immune responses or environmental stress, contributing to oxidative stress resistance.

Expression of sodC2 can be influenced by environmental conditions such as oxidative stress, metal availability, or growth phase. In some lineages, the copy may be subject to regulatory divergence relative to sodC1, and in a few cases the sodC2 gene may accumulate mutations that reduce function or become nonfunctional as a pseudogene. The presence of multiple sodC paralogs is generally interpreted as a potential for functional redundancy, diversification of regulation, or adaptation to different ecological niches.

Significance varies by organism. In pathogenic or commensal Gram-negative bacteria, periplasmic CuZnSODs, including sodC2 when present, are considered part of the oxidative stress defense system and can influence survival and, in some contexts, host interactions. The exact role of sodC2 is species-specific and may differ between strains.