Trypsin-like peptidase domain. This family includes trypsin like peptidase domains.

periplasmic serine protease, Do/DeqQ family. This family consists of a set proteins various designated DegP, heat shock protein HtrA, and protease DO. The ortholog in Pseudomonas aeruginosa is designated MucD and is found in an operon that controls mucoid phenotype. This family also includes the DegQ (HhoA) paralog in E. coli which can rescue a DegP mutant, but not the smaller DegS paralog, which cannot. Members of this family are located in the periplasm and have separable functions as both protease and chaperone. Members have a trypsin domain and two copies of a PDZ domain. This protein protects bacteria from thermal and other stresses and may be important for the survival of bacterial pathogens.// The chaperone function is dominant at low temperatures, whereas the proteolytic activity is turned on at elevated temperatures [Protein fate, Protein folding and stabilization, Protein fate, Degradation of proteins, peptides, and glycopeptides].

Trypsin-like serine proteases, typically periplasmic, contain C-terminal PDZ domain [Posttranslational modification, protein turnover, chaperones]

GDP-fucose protein O-fucosyltransferase. This is a family of conserved proteins representing the enzyme responsible for adding O-fucose to EGF (epidermal growth factor-like) repeats. Six highly conserved cysteines are present in O-FucT-1 as well as a DXD-like motif (ERD), conserved in mammals, Drosophila, and C. elegans. Both features are characteristic of several glycosyltransferase families. The enzyme is a membrane-bound protein released by proteolysis and, as for most glycosyltransferases, is strongly activated by manganese.