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185  structures 3932  species 9  interactions 18127  sequences 88  architectures

Clan: Met_repress (CL0057)


MetJ/Arc repressor superfamily Add an annotation

This superfamily contains the MetJ and Arc repressors that feature a ribbon-helix-helix DNA-binding motif with the beta-ribbon located in and recognising the major groove of operator DNA [1].

This clan contains 21 families and the total number of domains in the clan is 18127. The clan was built by A Bateman.

Literature references

  1. Murayama K, Orth P, de la Hoz AB, Alonso JC, Saenger W; , J Mol Biol 2001;314:789-796.: Crystal structure of omega transcriptional repressor encoded by Streptococcus pyogenes plasmid pSM19035 at 1.5 A resolution. PUBMED:11733997 EPMC:11733997


This clan contains the following 21 member families:

Arc CcdA DUF1662 DUF1778 DUF2191 DUF2610 DUF3423 DUF3924 HicB MetJ Omega_Repress ParD ParG PSK_trans_fac RelB RepB-RCR_reg RHH_1 RHH_2 RHH_3 RHH_4 TraY

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
RHH_1 (PF01402) 5913 (32.6%) View
RelB (PF04221) 2614 (14.4%) View
DUF1778 (PF08681) 1442 (8.0%) View
HicB (PF05534) 1200 (6.6%) View
RHH_2 (PF03693) 1166 (6.4%) View
MetJ (PF01340) 798 (4.4%) View
Arc (PF03869) 753 (4.2%) View
DUF2191 (PF09957) 685 (3.8%) View
CcdA (PF07362) 640 (3.5%) View
RHH_4 (PF13467) 610 (3.4%) View
DUF3423 (PF11903) 485 (2.7%) View
Pfam family Num. domains Alignment
RepB-RCR_reg (PF10723) 388 (2.1%) View
RHH_3 (PF12651) 354 (2.0%) View
PSK_trans_fac (PF07704) 347 (1.9%) View
TraY (PF05509) 257 (1.4%) View
Omega_Repress (PF07764) 125 (0.7%) View
ParG (PF09274) 92 (0.5%) View
DUF3924 (PF13062) 84 (0.5%) View
DUF1662 (PF07878) 70 (0.4%) View
DUF2610 (PF11020) 66 (0.4%) View
ParD (PF09386) 38 (0.2%) View
Total: 21 Total: 18127 Clan alignment

Please note: Clan alignments can be very large and can cause problems for some browsers. Read the note above before viewing.

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...



There are 9 interactions for this clan. More...

Interacting families
CcdA CcdA
ParD ParD
DUF1778 DUF1778
Omega_Repress Omega_Repress
MetJ MetJ
ParG ParG
Arc Arc


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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