cell actin for propulsion to move directly from cell to cell using a cellular mechanism known as paracytophagy, similarly to the bacterial pathogen Listeria monocytogenes. Shigella flexneri is able to inhibit the acute inflammatory response in the initial stage of infection by using an effector protein, OspI, which is encoded by ORF169b on the Shigella large plasmid and secreted by the type III secretion system. It dampens the inflammatory response during bacterial invasion by suppressing the TNF-α-receptor-associated factor 6 (TRAF6)-mediated signalling pathway. OspI has glutamine deamidase activity, and is able to selectively deaminate glutamine at position 100 in UBC13 to glutamate, and this results in a failure of the E2 ubiquitin-conjugating activity which is required for TRAF6 activation. References External links Type strain of Shigella flexneri at BacDive - the Bacterial Diversity Metadatabase Enterobacteriaceae Bacteria described in 1919