FIG. 4.

A comparison of enzymatically regulated versus stochastic S-nitrosylation. Under conditions where NO is generated intracellularly by nitrate reductase, S-nitrosylation of proteins is enzymatically regulated by the S-nitrosylase, Hcp. S-nitrosylation by Hcp plays an essential role in bacterial motility and metabolism. By contrast, unregulated and aberrant S-nitrosylation by exogenous NO/RNS, which may occur via multiple chemical routes such as during host defense against infection, leads to nitrosative stress. RNS, reactive nitrogen species.