This entry represents bacterial immunity proteins that in are encoded by the PAAR2 cluster [1] and have been named Type VI immunity for VRR-NUC (TsiV). These proteins form an effector-immunity pair with TseV (type VI effector VRR-NUC), the TseV-TsiV pair [1,2]. These are alpha+beta class of proteins whose surface is mainly electronegative with a a hydrophobic core formed by the N-terminal region [1].

1: The Pseudomonas aeruginosa PAAR2 cluster encodes a putative VRR-NUC domain-containing effector. Wang S, Geng Z, Zhang H, She Z, Dong Y; FEBS J. 2021;288:5755-5767. PMID:33838074

2: Antibacterial T6SS effectors with a VRR-Nuc domain are structure-specific nucleases. Hespanhol JT, Sanchez-Limache DE, Nicastro GG, Mead L, Llontop EE, Chagas-Santos G, Farah CS, de Souza RF, Galhardo RDS, Lovering AL, Bayer-Santos E; Elife. 2022;11:e82437. PMID:36226828