This entry represents the phosphodiesterase (PDE) domain found in the bacterial ubiquitinating enzymes, which belong to the SidE family. This domain catalyses the conjugation of ADP-ribosylated ubiquitin (ADPR-Ub), previously synthesised by the mono-ADP-ribosyltransferase (mART) domain, to a serine residue on substrates to generate a protein-phosphoribosyl-Ub (PR-Ub) product. These pathogen proteins are secreted bacterial effector proteins, which are translocated inside the host cell using the Dot/Icm secretion system [1,2]. The SidE family of enzymes carry out ubiquitination of host cell proteins in an E1/E2-independent manner [2,3].

1: Mechanism of phosphoribosyl-ubiquitination mediated by a single Legionella effector. Akturk A, Wasilko DJ, Wu X, Liu Y, Zhang Y, Qiu J, Luo ZQ, Reiter KH, Brzovic PS, Klevit RE, Mao Y; Nature. 2018;557:729-733. PMID:29795346

2: Ubiquitination independent of E1 and E2 enzymes by bacterial effectors. Qiu J, Sheedlo MJ, Yu K, Tan Y, Nakayasu ES, Das C, Liu X, Luo ZQ; Nature. 2016;533:120-124. PMID:27049943

3: Revisiting Bacterial Ubiquitin Ligase Effectors: Weapons for Host Exploitation. Pisano A, Albano F, Vecchio E, Renna M, Scala G, Quinto I, Fiume G; Int J Mol Sci. 2018; [Epub ahead of print] PMID:30428531