This family is conserved in Enterobacteriaceae. It is one of a series of proteins, expressed by these bacteria in response to stress, that help to regulate Sigma-S, the stationary phase sigma factor of Escherichia coli and Salmonella. IraP is essential for Sigma-S stabilization in some but not all starvation conditions.
Jiyao W et al.(2023). "The conserved domain database in 2023.",