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26  structures 3734  species 0  interactions 17602  sequences 217  architectures

Clan: TolA-TonB-Cterm (CL0428)


TolA/TonB C-terminal Add an annotation

This clan contains the TolA and TonB C terminal domains. These domains adopt a structure containing anti-parallel beta sheets with some alpha helical regions. The TolA family contains an extra N-terminal helix over the common fold, and the TonB is an isolated domain that can form different segment-swapped dimers depending on the fragment length [1].

This clan contains 3 families and the total number of domains in the clan is 17602. The clan was built by J Mistry and RD Finn.

Literature references

  1. Sean Peacock R, Weljie AM, Peter Howard S, Price FD, Vogel HJ;, J Mol Biol. 2005;345:1185-1197.: The solution structure of the C-terminal domain of TonB and interaction studies with TonB box peptides. PUBMED:15644214 EPMC:15644214


This clan contains the following 3 member families:

TolA TonB_2 TonB_C

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
TonB_C (PF03544) 14256 (81.0%) View
TonB_2 (PF13103) 2924 (16.6%) View
TolA (PF06519) 422 (2.4%) View
Total: 3 Total: 17602 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...



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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