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12  structures 2553  species 0  interactions 3069  sequences 10  architectures

Clan: T3SS-Chaperone (CL0419)


Type III secretion system types a and b chaperone Add an annotation

Type III secretion systems of the two forms, a - translocation-associated, and b - bacterial flagellum, share homology between comparable parts. This superfamily includes the chaperone proteins FliJ and HrpB7.

This clan contains 4 families and the total number of domains in the clan is 3069. The clan was built by RD Finn and P Coggill.

Literature references

  1. Desvaux M, Hebraud M, Henderson IR, Pallen MJ;, Trends Microbiol. 2006;14:157-160.: Type III secretion: what's in a name?. PUBMED:16533600 EPMC:16533600


This clan contains the following 4 member families:

FliJ HrpB7 YscO YscO-like

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
FliJ (PF02050) 2877 (93.7%) View
YscO (PF07321) 98 (3.2%) View
HrpB7 (PF09486) 52 (1.7%) View
YscO-like (PF16789) 42 (1.4%) View
Total: 4 Total: 3069 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.

Loading structure mapping...