Protein Family Models

AbrB-like is a family of small proteins that operate in conjunction with a cognate toxin molecule. The commonly attributed role of toxin-antitoxin systems is to maintain low-copy number plasmids from one generation to the next. Such gene-pairs are also found on chromosomes and to be associated with a number of biological functions such as: reduction of protein synthesis, gene regulation and retardation of cell growth under nutritional stress [1]. This family includes proteins from a number of different pairings, eg MazE, AbrB, VapB [2], PhoU, PemI-like and SpoVT. MazE is the antidote to the toxin MazF of E. coli. MazE-MazF in E. coli is a regulated prokaryotic chromosomal addiction module. MazE antidote is degraded by the ClpPA protease of the bacterial proteasome. MazE-MazF is thought to play a role in programmed cell death when cells suffer nutrient deprivation [3], and MazE-MazF modules have also been implicated in the bacteriostatic effects of other addiction modules [3]. [1]. 15101989. Identification of AbrB-regulated genes involved in biofilm formation by Bacillus subtilis. Hamon MA, Stanley NR, Britton RA, Grossman AD, Lazazzera BA;. Mol Microbiol. 2004;52:847-860. [2]. 22140099. Crystal structure of the DNA-bound VapBC2 antitoxin/toxin pair from Rickettsia felis. Mate MJ, Vincentelli R, Foos N, Raoult D, Cambillau C, Ortiz-Lombardia M;. Nucleic Acids Res. 2012;40:3245-3258. [3]. 12718874. Crystal structure of the MazE/MazF complex: molecular bases of antidote-toxin recognition. Kamada K, Hanaoka F, Burley SK;. Mol Cell. 2003;11:875-884. (from Pfam)

Date:

2024-10-16

AbrB/MazE/SpoVT family DNA-binding domain-containing protein similar to Bacillus subtilis transition state regulatory protein AbrB and Mycobacterium tuberculosis antitoxin VapB27, the antitoxin component of a type II toxin-antitoxin system whose cognate toxin is VapC27

Date:

2021-01-25

This DNA-binding domain family includes AbrB, a transition state regulator in Bacillus subtilis, whose DNA-binding domain structure in solution was determined by NMR. The domain binds DNA as a dimer in what is termed a looped-hinge helix fold. Some members of the family have two copies of the domain in tandem. The domain is found usually at the N-terminus of a small protein. This model excludes members of family TIGR02609.

Date:

2021-04-27