Class IA type III secretion system chaperone protein, similar to Pseudomonas aeruginosa SpcU
This family includes type III secretion system (T3SS) chaperone proteins similar to Pseudomonas aeruginosa SpcU and similar proteins. In P. aeruginosa, a multidrug resistant pathogen associated with serious illnesses such as ventilator-associated pneumonia and various sepsis syndromes, the T3SS allows injection of effector protein ExoU, one of the most aggressive toxins injected by a T3SS, into the cytosol of target eukaryotic cells, leading to rapid cell necrosis. Chaperone SpcU binds the cytotoxin ExoU, which is a broad-specificity phospholipase A2 (PLA2) and lysophospholipase, and maintains the N-terminus of ExoU in an unfolded state which is required for secretion.
Jiyao W et al.(2023). "The conserved domain database in 2023.",