Protein-glutamine deamidase effector that inhibits the host cell cycle and other key cellular processes such as the actin network and programmed-cell death (PubMed:19308257, PubMed:22691497). Acts by mediating the side chain deamidation of 'Gln-40' of host NEDD8, converting it to glutamate, thereby abolishing the activity of cullin-RING-based E3 ubiquitin-protein ligase complexes (CRL complexes) (PubMed:22691497). Inactivation of CRL complexes prevents ubiquitination and subsequent degradation of the cyclin-dependent kinase inhibitors CDKN1A/p21 and CDKN1B/p27, leading to G1 and G2 cell cycle arrests in host cells (PubMed:19308257). Also able to catalyze deamidation of 'Gln-40' of host ubiquitin in vitro; however, NEDD8 constitutes the preferred substrate in vivo (By similarity). H2O + L-glutaminyl-[protein] = L-glutamyl-[protein] + NH4(+) Secreted via the type III secretion system (TTSS). Belongs to the Cif family.