PDZ domain of trypsin-like serine proteases, such as DegP/HtrA, which are oligomeric proteins involved in heat-shock response, chaperone function, and apoptosis. May be responsible for substrate recognition and/or binding, as most PDZ domains bind C-terminal polypeptides, though binding to internal (non-C-terminal) polypeptides and even to lipids has been demonstrated. In this subfamily of protease-associated PDZ domains a C-terminal beta-strand forms the peptide-binding groove base, a circular permutation with respect to PDZ domains found in Eumetazoan signaling proteins.

PDZ domain.

Periplasmic serine protease, S1-C subfamily, contain C-terminal PDZ domain [Posttranslational modification, protein turnover, chaperones].

Right handed beta helix region. This region contains a parallel beta helix region that shares some similarity with Pectate lyases.

Domain present in PSD-95, Dlg, and ZO-1/2. Also called DHR (Dlg homologous region) or GLGF (relatively well conserved tetrapeptide in these domains). Some PDZs have been shown to bind C-terminal polypeptides; others appear to bind internal (non-C-terminal) polypeptides. Different PDZs possess different binding specificities.