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3  structures 2079  species 0  interactions 3986  sequences 25  architectures

Clan: Phage_TACs (CL0567)


Phage tail assembly chaperone Add an annotation

This superfamily is characterised by only distantly related families of tail assembly chaperones or TACs. Most bacteriophages possess a long tail that is either contractile as in the Siphoviridae family or contractile as in the Myoviridae family. TACs are required for the morphogenesis of all long-tailed phages. All the studied TACs form spiral quaternary rings that have arisen through diverging sequences and oligomerisation mechanisms. The proposed function in all cases, however, is for the TAC to coat the tape-measure protein to prevent it from forming unproductive complexes or precipitating before the tail tube protein has been incorporated [1,2].

This clan contains 14 families and the total number of domains in the clan is 3986. The clan was built by A Davidson and P Coggill.

Literature references

  1. Pell LG, Kanelis V, Donaldson LW, Howell PL, Davidson AR;, Proc Natl Acad Sci U S A. 2009;106:4160-4165.: The phage lambda major tail protein structure reveals a common evolution for long-tailed phages and the type VI bacterial secretion system. PUBMED:19251647 EPMC:19251647
  2. Pell LG, Cumby N, Clark TE, Tuite A, Battaile KP, Edwards AM, Chirgadze NY, Davidson AR, Maxwell KL;, J Mol Biol. 2013;425:2436-2449.: A conserved spiral structure for highly diverged phage tail assembly chaperones. PUBMED:23542344 EPMC:23542344


This clan contains the following 14 member families:

Phage_TAC_1 Phage_TAC_10 Phage_TAC_11 Phage_TAC_12 Phage_TAC_13 Phage_TAC_14 Phage_TAC_2 Phage_TAC_3 Phage_TAC_4 Phage_TAC_5 Phage_TAC_6 Phage_TAC_7 Phage_TAC_8 Phage_TAC_9

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
Phage_TAC_11 (PF11836) 991 (24.9%) View
Phage_TAC_7 (PF10109) 822 (20.6%) View
Phage_TAC_6 (PF09550) 722 (18.1%) View
Phage_TAC_5 (PF08890) 451 (11.3%) View
Phage_TAC_12 (PF12363) 308 (7.7%) View
Phage_TAC_4 (PF08748) 246 (6.2%) View
Phage_TAC_3 (PF06896) 114 (2.9%) View
Phage_TAC_13 (PF16459) 72 (1.8%) View
Phage_TAC_1 (PF06222) 71 (1.8%) View
Phage_TAC_10 (PF10963) 67 (1.7%) View
Phage_TAC_2 (PF06894) 56 (1.4%) View
Phage_TAC_14 (PF16462) 32 (0.8%) View
Phage_TAC_9 (PF10876) 28 (0.7%) View
Phage_TAC_8 (PF10666) 6 (0.2%) View
Total: 14 Total: 3986 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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