This family of proteins includes the type VI secretion system (T6SS) immunity protein TsiT from Pseudomonas aeruginosa (Swiss:Q9HXA5) and similar proteins mainly found in proteobacteria. TsiT, which belongs to the Imm52 family, can suppress the virulence of TseT [2]. This protein adopts a beta-sandwich fold with nine alpha-helices and an eight-stranded antiparallel central beta-sheet. It has a large electro-negative pocket with hydrophobic surroundings that play a role in the interaction with TseT [3,4]. Proteins containing this domain are present in bacterial polymorphic toxin systems as an immediate gene neighbour of the toxin gene, usually containing a domain of the Tox-REase-5 family [1]. [1]. 22731697. 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. [2]. 29632369. A type VI secretion system effector delivery mechanism dependent on PAAR and a chaperone-co-chaperone complex. Burkinshaw BJ, Liang X, Wong M, Le ANH, Lam L, Dong TG;. Nat Microbiol. 2018;3:632-640. [3]. 30834616. Structural characterization of the Imm52 family protein TsiT in Pseudomonas aeruginosa. She Z, Geng Z, Xu JH, Li YH, Dong YH;. Protein Sci. 2019;28:971-975. [4]. 34371041. Structure and SAXS studies unveiled a novel inhibition mechanism of the Pseudomonas aeruginosa T6SS TseT-TsiT complex. Wen H, Liu G, Geng Z, Zhang H, Li Y, She Z, Dong Y;. Int J Biol Macromol. 2021;188:450-459. (from Pfam)
- Date:
- 2024-10-16