This family of proteins regulate mRNA abundance by binding to RNaseE and inhibiting its endonucleolytic activity [1-2]. A subset of these proteins are predicted to function as immunity proteins [3].

1: Differential modulation of E. coli mRNA abundance by inhibitory proteins that alter the composition of the degradosome. Gao J, Lee K, Zhao M, Qiu J, Zhan X, Saxena A, Moore CJ, Cohen SN, Georgiou G; Mol Microbiol. 2006;61:394-406. PMID:16771842

2: Inhibitory effects of RraA and RraB on RNAse E-related enzymes imply conserved functions in the regulated enzymatic cleavage of RNA. Yeom JH, Go H, Shin E, Kim HL, Han SH, Moore CJ, Bae J, Lee K; FEMS Microbiol Lett. 2008;285:10-15. PMID:18510556

3: Polymorphic toxin systems: comprehensive characterization of trafficking modes, processing, mechanisms of action, immunity and ecology using comparative genomics. Zhang D, de Souza RF, Anantharaman V, Iyer LM, Aravind L; Biol Direct. 2012;7:18. PMID:22731697