Ubiquitin Chains Modified by the Bacterial Ligase SdeA Are Protected from Deubiquitinase Hydrolysis.

Abstract

The SidE family of Legionella pneumophila effectors is a unique group of ubiquitin-modifying enzymes. Along with catalyzing NAD+-dependent ubiquitination of certain host proteins independent of the canonical E1/E2/E3 pathway, they have also been shown to produce phosphoribosylated free ubiquitin. This modified ubiquitin product is incompatible with conventional E1/E2/E3 ubiquitination processes, with the potential to lock down various cellular functions that are dependent on ubiquitin signaling. Here, we show that in addition to free ubiquitin, Lys63-, Lys48-, Lys11-, and Met1-linked diubiquitin chains are also modified by SdeA in a similar fashion. Both the proximal and distal ubiquitin moieties are targeted in the phosphoribosylation reaction. Furthermore, this renders the ubiquitin chains unable to be processed by a variety of deubiquitinating enzymes. These observations broaden the scope of SdeA's modulatory functions during Legionella infection.

DOI: 10.1021/acs.biochem.7b00664

Cite this paper

@article{Puvar2017UbiquitinCM, title={Ubiquitin Chains Modified by the Bacterial Ligase SdeA Are Protected from Deubiquitinase Hydrolysis.}, author={Kedar Puvar and Yiyang Zhou and Jiazhang Qiu and Zhao-Qing Luo and Mary J Wirth and Chittaranjan Das}, journal={Biochemistry}, year={2017}, volume={56 36}, pages={4762-4766} }