FEATURES

FAMILY

DESCRIPTION

Also known as RELB_ECOLI, relB. Antitoxin component of a type II toxin-antitoxin (TA) system. Counteracts the effect of cognate toxin RelE via direct protein-protein interaction, preventing RelE from entering the ribosome A site and thus inhibiting its endoribonuclease activity. An autorepressor of relBE operon transcription. 2 RelB dimers bind to 2 operator sequences; DNA-binding and repression is stronger when complexed with toxin/corepressor RelE by conditional cooperativity (PubMed:18501926, PubMed:22981948). Increased transcription rate of relBE and activation of relE is consistent with a lower level of RelB in starved cells due to degradation of RelB by protease Lon., Seems to be a principal mediator of cell death in liquid media. Homotetramer formed by dimerization of dimers in solution (PubMed:19747491, PubMed:18501926). Forms an RelB(2)-RelE(2) heterotetramer (PubMed:18501926, PubMed:22981948). Also forms an RelB(2)-RelE heterotrimer (PubMed:18532983, PubMed:19747491). The RelB(2)-RelE complex is probably the one that binds DNA and represses transcription, possibly as 2 heterotrimers, 1 bound to each of 2 operators (PubMed:22981948, PubMed:19747491).

EXTERNAL LINKS

relB

Antitoxin RelB

relB

Molecular Synopsis