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

The term VapB has been used for the antitoxin component of various type II toxin-antitoxin systems called VapBC but showing little or no sequence identity. The family described here includes member proteins such as STM3034 from Salmonella enterica LT2 and VapB2 from Haemophilus influenzae, and is seeming unrelated to proteins called VapB in Mycobacterium tuberculosis.

Gene:

vapB

Date:

2021-07-28

antitoxin similar to Shigella flexneri VapB, an antitoxin component of a toxin-antitoxin (TA) module

Date:

2015-12-03