This entry represents the C-terminal domain of antitoxin components of a type II toxin-antitoxin (TA) system, including Xre from Pseudomonas putida, MbcA from Mycobacterium sp. and ParS from Sphingobium sp. [1,2,3,4]. This domain interacts with the toxin component and sterically blocks its active site, neutralising its effect [2,3]. These antitoxins also have a HTH domain at the N-terminal.

1: ParST is a widespread toxin-antitoxin module that targets nucleotide metabolism. Piscotta FJ, Jeffrey PD, Link AJ; Proc Natl Acad Sci U S A. 2019;116:826-834. PMID:30598453

2: An NAD(+) Phosphorylase Toxin Triggers Mycobacterium tuberculosis Cell Death. Freire DM, Gutierrez C, Garza-Garcia A, Grabowska AD, Sala AJ, Ariyachaokun K, Panikova T, Beckham KSH, Colom A, Pogenberg V, Cianci M, Tuukkanen A, Boudehen YM, Peixoto A, Botella L, Svergun DI, Schnappinger D, Schneider TR, Genevaux P, de Carvalho LPS, Wilmanns M, Parret AHA, Neyrolles O; Mol Cell. 2019;73:1282-1291. PMID:30792174

3: The RES domain toxins of RES-Xre toxin-antitoxin modules induce cell stasis by degrading NAD+. Skjerning RB, Senissar M, Winther KS, Gerdes K, Brodersen DE; Mol Microbiol. 2019;111:221-236. PMID:30315706

4: Bacterial type II toxin-antitoxin systems acting through post-translational modifications. Zhang SP, Feng HZ, Wang Q, Kempher ML, Quan SW, Tao X, Niu S, Wang Y, Feng HY, He YX; Comput Struct Biotechnol J. 2020;19:86-93. PMID:33384857