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13  structures 1443  species 0  interactions 10628  sequences 147  architectures

Clan: PRD (CL0166)


PRD domain superfamily Add an annotation

The PRD domain (for PTS Regulation Domain), is the phosphorylatable regulatory domain found in bacterial transcriptional antiterminator of the BglG family as well as in activators such as MtlR and LevR. The PRD domain is phosphorylated on a conserved histidine residue. 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 (Pfam:PF03123, see also comments for this family)) or DNA (for activators), and a duplicated PRD module which is phosphorylated on conserved histidines by the sugar phosphotransferase system (PTS) in response to the availability of carbon source. The phosphorylations are thought to modify the stability of the dimeric proteins and thereby the RNA- or DNA-binding activity of the effector domain.

This clan contains 2 families and the total number of domains in the clan is 10628. The clan was built by A Bateman.


This clan contains the following 2 member families:


External database links

Domain organisation

Below is a listing of the unique domain organisations or architectures from this clan. More...

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The table below shows the number of occurrences of each domain throughout the sequence database. More...

Pfam family Num. domains Alignment
PRD (PF00874) 10576 (99.5%) View
PRD_Mga (PF08270) 52 (0.5%) View
Total: 2 Total: 10628 Clan alignment

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Family relationships

This diagram shows the relationships between members of this clan. More...

Species distribution

Tree controls


This tree shows the occurrence of the domains in this clan across different species. More...



For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the MSD group, to allow us to map Pfam domains onto UniProt three-dimensional structures. The table below shows the mapping between the Pfam families in this clan, the corresponding UniProt entries, and the region of the three-dimensional structures that are available for that sequence.

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