pfam00874: PRD (This model is not part of the current CDD release)
PRD domain
The PRD domain (for PTS Regulation Domain), is the phosphorylatable regulatory domain found in bacterial transcriptional antiterminator such as BglG, SacY and LicT, as well as in activators such as MtlR and LevR. The PRD is phosphorylated on one or two conserved histidine residues. PRD-containing proteins are involved in the regulation of catabolic operons in Gram+ and Gram- bacteria and are often characterised by a short N-terminal effector domain that binds to either RNA (CAT-RBD for antiterminators pfam03123) or DNA (for activators), and a duplicated PRD module which is phosphorylated by the sugar phosphotransferase system (PTS) in response to the availability of carbon source. The phosphorylations modify the conformation and stability of the dimeric proteins and thereby the RNA- or DNA-binding activity of the effector domain. The structure of the LicT PRD domains has been solved in both the active (pdb:1h99) and inactive state (pdb:1tlv), revealing massive structural rearrangements upon activation.
Jiyao W et al.(2023). "The conserved domain database in 2023.",