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9  structures 509  species 1  interaction 640  sequences 4  architectures

Family: CcdA (PF07362)

Summary: Post-segregation antitoxin CcdA

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This tab holds the annotation information that is stored in the Pfam database. As we move to using Wikipedia as our main source of annotation, the contents of this tab will be gradually replaced by the Wikipedia tab.

Post-segregation antitoxin CcdA Provide feedback

This family consists of several Enterobacterial post-segregation antitoxin CcdA proteins. The F plasmid-carried bacterial toxin, the CcdB protein, is known to act on DNA gyrase in two different ways. CcdB poisons the gyrase-DNA complex, blocking the passage of polymerases and leading to double-strand breakage of the DNA. Alternatively, in cells that overexpress CcdB, the A subunit of DNA gyrase (GyrA) has been found as an inactive complex with CcdB. Both poisoning and inactivation can be prevented and reversed in the presence of the F plasmid-encoded antidote, the CcdA protein [1].

Literature references

  1. Bahassi EM, O'Dea MH, Allali N, Messens J, Gellert M, Couturier M; , J Biol Chem 1999;274:10936-10944.: Interactions of CcdB with DNA gyrase. Inactivation of Gyra, poisoning of the gyrase-DNA complex, and the antidote action of CcdA. PUBMED:10196173 EPMC:10196173


External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR009956

This entry consists of several Enterobacterial post-segregation antitoxin CcdA proteins. The F plasmid-carried bacterial toxin, the CcdB protein, is known to act on DNA gyrase in two different ways. CcdB poisons the gyrase-DNA complex, blocking the passage of polymerases and leading to double-strand breakage of the DNA. Alternatively, in cells that overexpress CcdB, the A subunit of DNA gyrase (GyrA) has been found as an inactive complex with CcdB. Both poisoning and inactivation can be prevented and reversed in the presence of the F plasmid-encoded antidote, the CcdA protein [PUBMED:10196173].

Domain organisation

Below is a listing of the unique domain organisations or architectures in which this domain is found. More...

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Pfam Clan

This family is a member of clan Met_repress (CL0057), which has the following description:

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].

The clan contains the following 21 members:

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

Alignments

We store a range of different sequence alignments for families. As well as the seed alignment from which the family is built, we provide the full alignment, generated by searching the sequence database using the family HMM. We also generate alignments using four representative proteomes (RP) sets, the NCBI sequence database, and our metagenomics sequence database. More...

View options

We make a range of alignments for each Pfam-A family. You can see a description of each above. You can view these alignments in various ways but please note that some types of alignment are never generated while others may not be available for all families, most commonly because the alignments are too large to handle.

  Seed
(25)
Full
(640)
Representative proteomes NCBI
(324)
Meta
(32)
RP15
(27)
RP35
(64)
RP55
(88)
RP75
(114)
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1Cannot generate PP/Heatmap alignments for seeds; no PP data available

Key: ✓ available, x not generated, not available.

Format an alignment

  Seed
(25)
Full
(640)
Representative proteomes NCBI
(324)
Meta
(32)
RP15
(27)
RP35
(64)
RP55
(88)
RP75
(114)
Alignment:
Format:
Order:
Sequence:
Gaps:
Download/view:

Download options

We make all of our alignments available in Stockholm format. You can download them here as raw, plain text files or as gzip-compressed files.

  Seed
(25)
Full
(640)
Representative proteomes NCBI
(324)
Meta
(32)
RP15
(27)
RP35
(64)
RP55
(88)
RP75
(114)
Raw Stockholm Download   Download   Download   Download   Download   Download   Download   Download  
Gzipped Download   Download   Download   Download   Download   Download   Download   Download  

You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.

External links

MyHits provides a collection of tools to handle multiple sequence alignments. For example, one can refine a seed alignment (sequence addition or removal, re-alignment or manual edition) and then search databases for remote homologs using HMMER3.

HMM logo

HMM logos is one way of visualising profile HMMs. Logos provide a quick overview of the properties of an HMM in a graphical form. You can see a more detailed description of HMM logos and find out how you can interpret them here. More...

Trees

This page displays the phylogenetic tree for this family's seed alignment. We use FastTree to calculate neighbour join trees with a local bootstrap based on 100 resamples (shown next to the tree nodes). FastTree calculates approximately-maximum-likelihood phylogenetic trees from our seed alignment.

Note: You can also download the data file for the tree.

Curation and family details

This section shows the detailed information about the Pfam family. You can see the definitions of many of the terms in this section in the glossary and a fuller explanation of the scoring system that we use in the scores section of the help pages.

Curation View help on the curation process

Seed source: Pfam-B_20349 (release 10.0)
Previous IDs: none
Type: Family
Author: Moxon SJ
Number in seed: 25
Number in full: 640
Average length of the domain: 67.90 aa
Average identity of full alignment: 35 %
Average coverage of the sequence by the domain: 86.53 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 21.4 21.4
Trusted cut-off 21.4 21.4
Noise cut-off 21.2 21.2
Model length: 72
Family (HMM) version: 7
Download: download the raw HMM for this family

Species distribution

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This visualisation provides a simple graphical representation of the distribution of this family across species. You can find the original interactive tree in the adjacent tab. More...

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Interactions

There is 1 interaction for this family. More...

CcdA

Structures

For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the CcdA domain has been found. There are 9 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein seqence.

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