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210  structures 2686  species 14  interactions 11686  sequences 68  architectures

Clan: Pilus (CL0327)


Pilus subunit Add an annotation

This is a clan contains bacterial pilus subunits and proteins involved in secretion. Pili proteins enable the transfer of plasmid between bacteria. The families in this clan adopt an alpha helical structure which is packed against a beta sheet [2-3].

This clan contains 13 families and the total number of domains in the clan is 11686. The clan was built by J Mistry.

Literature references

  1. Telford JL, Barocchi MA, Margarit I, Rappuoli R, Grandi G; , Nat Rev Microbiol. 2006;4:509-519.: Pili in gram-positive pathogens. PUBMED:16778837 EPMC:16778837
  2. Xu XF, Tan YW, Lam L, Hackett J, Zhang M, Mok YK; , J Biol Chem. 2004;279:31599-31605.: NMR structure of a type IVb pilin from Salmonella typhi and its assembly into pilus. PUBMED:15159389 EPMC:15159389
  3. Hazes B, Sastry PA, Hayakawa K, Read RJ, Irvin RT; , J Mol Biol. 2000;299:1005-1017.: Crystal structure of Pseudomonas aeruginosa PAK pilin suggests a main-chain-dominated mode of receptor binding. PUBMED:10843854 EPMC:10843854


This clan contains the following 13 member families:

Bundlin ComP_DUS GspH Pilin Pilin_GH Pilin_PilX PilJ_C PilM PilS T2SSG T2SSI T2SSJ TcpA

External database links

Domain organisation

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

Loading domain graphics...


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

Pfam family Num. domains Alignment
T2SSG (PF08334) 2952 (25.3%) View
GspH (PF12019) 2837 (24.3%) View
ComP_DUS (PF16732) 1619 (13.9%) View
Pilin (PF00114) 1521 (13.0%) View
T2SSI (PF02501) 1114 (9.5%) View
T2SSJ (PF11612) 947 (8.1%) View
Pilin_GH (PF16734) 347 (3.0%) View
PilS (PF08805) 222 (1.9%) View
PilM (PF07419) 82 (0.7%) View
PilJ_C (PF18223) 22 (0.2%) View
Pilin_PilX (PF11530) 13 (0.1%) View
TcpA (PF05946) 10 (0.1%) View
Bundlin (PF05307) 0 (0.0%) View
Total: 13 Total: 11686 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 14 interactions for this clan. More...

Interacting families
Bundlin TcpA
GspH GspH
Pilin Pilin
Pilin_PilX Pilin_PilX
PilM PilM
PilS PilS
TcpA TcpA


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...