Summary: Toxin Fst, type I toxin-antitoxin system
This is the Wikipedia entry entitled "Par stability determinant". More...
The Wikipedia text that you see displayed here is a download from Wikipedia. This means that the information we display is a copy of the information from the Wikipedia database. The button next to the article title ("Edit Wikipedia article") takes you to the edit page for the article directly within Wikipedia. You should be aware you are not editing our local copy of this information. Any changes that you make to the Wikipedia article will not be displayed here until we next download the article from Wikipedia. We currently download new content on a nightly basis.
Does Pfam agree with the content of the Wikipedia entry ?
Pfam has chosen to link families to Wikipedia articles. In some case we have created or edited these articles but in many other cases we have not made any direct contribution to the content of the article. The Wikipedia community does monitor edits to try to ensure that (a) the quality of article annotation increases, and (b) vandalism is very quickly dealt with. However, we would like to emphasise that Pfam does not curate the Wikipedia entries and we cannot guarantee the accuracy of the information on the Wikipedia page.
Editing Wikipedia articles
Before you edit for the first time
Wikipedia is a free, online encyclopedia. Although anyone can edit or contribute to an article, Wikipedia has some strong editing guidelines and policies, which promote the Wikipedia standard of style and etiquette. Your edits and contributions are more likely to be accepted (and remain) if they are in accordance with this policy.
You should take a few minutes to view the following pages:
How your contribution will be recorded
Anyone can edit a Wikipedia entry. You can do this either as a new user or you can register with Wikipedia and log on. When you click on the "Edit Wikipedia article" button, your browser will direct you to the edit page for this entry in Wikipedia. If you are a registered user and currently logged in, your changes will be recorded under your Wikipedia user name. However, if you are not a registered user or are not logged on, your changes will be logged under your computer's IP address. This has two main implications. Firstly, as a registered Wikipedia user your edits are more likely seen as valuable contribution (although all edits are open to community scrutiny regardless). Secondly, if you edit under an IP address you may be sharing this IP address with other users. If your IP address has previously been blocked (due to being flagged as a source of 'vandalism') your edits will also be blocked. You can find more information on this and creating a user account at Wikipedia.
If you have problems editing a particular page, contact us at email@example.com and we will try to help.
The community annotation is a new facility of the Pfam web site. If you have problems editing or experience problems with these pages please contact us.
Par stability determinant Edit Wikipedia article
|Secondary structure of RNAII|
|RNA type||Gene; antitoxin|
|Fst Type I toxin-antitoxin system|
The par stability determinant is a 400 bp locus of the pAD1 plasmid which encodes a type I toxin-antitoxin system in Enterococcus faecalis. It was the first such plasmid addiction module to be found in gram-positive bacteria.
The par locus contains two genes: fst which encodes a 33-amino acid toxic protein and a gene for RNAII, the small RNA anti-toxin which inhibits fst translation. The two genes are found on opposite DNA strands and share a 5' region which is where they are thought to have an antisense interaction. Their RNA secondary structures have been predicted computationally, the complementary regions appear to be presented on exposed loops for interaction.
par maintains pAD1 by means of post-segregational killing (PSK). If a daughter cell does not inherit the par locus, the unstable RNAII will quickly degrade leaving the long-lived fst toxin to damage or kill the daughter cell.
See also 
- Weaver KE, Walz KD, Heine MS (November 1998). "Isolation of a derivative of Escherichia coli-Enterococcus faecalis shuttle vector pAM401 temperature sensitive for maintenance in E. faecalis and its use in evaluating the mechanism of pAD1 par-dependent plasmid stabilization". Plasmid 40 (3): 225–32. doi:10.1006/plas.1998.1368. PMID 9806859.
- Weaver KE, Jensen KD, Colwell A, Sriram SI (April 1996). "Functional analysis of the Enterococcus faecalis plasmid pAD1-encoded stability determinant par". Mol. Microbiol. 20 (1): 53–63. doi:10.1111/j.1365-2958.1996.tb02488.x. PMID 8861204.
- Shokeen S, Greenfield TJ, Ehli EA, Rasmussen J, Perrault BE, Weaver KE (March 2009). "An intramolecular upstream helix ensures the stability of a toxin-encoding RNA in Enterococcus faecalis". J. Bacteriol. 191 (5): 1528–36. doi:10.1128/JB.01316-08. PMC 2648210. PMID 19103923. Retrieved 2010-09-20.
- Greenfield TJ, Ehli E, Kirshenmann T, Franch T, Gerdes K, Weaver KE (August 2000). "The antisense RNA of the par locus of pAD1 regulates the expression of a 33-amino-acid toxic peptide by an unusual mechanism". Mol. Microbiol. 37 (3): 652–60. doi:10.1046/j.1365-2958.2000.02035.x. PMID 10931358. Retrieved 2010-09-20.
- Gerdes K, Gultyaev AP, Franch T, Pedersen K, Mikkelsen ND (1997). "Antisense RNA-regulated programmed cell death". Annu. Rev. Genet. 31: 1–31. doi:10.1146/annurev.genet.31.1.1. PMID 9442888.
Further reading 
- Gerdes K, Gultyaev AP, Franch T, Pedersen K, Mikkelsen ND (1997). "Antisense RNA-regulated programmed cell death". Annu. Rev. Genet. 31: 1–31. doi:10.1146/annurev.genet.31.1.1. PMID 9442888. Retrieved 2010-08-09.
- Poulsen LK, Larsen NW, Molin S, Andersson P (November 1989). "A family of genes encoding a cell-killing function may be conserved in all gram-negative bacteria". Mol. Microbiol. 3 (11): 1463–72. doi:10.1111/j.1365-2958.1989.tb00131.x. PMID 2693900.
- Hayes F (September 2003). "Toxins-antitoxins: plasmid maintenance, programmed cell death, and cell cycle arrest". Science 301 (5639): 1496–9. doi:10.1126/science.1088157. PMID 12970556. Retrieved 2010-08-10.
- Gerdes K, Rasmussen PB, Molin S (May 1986). "Unique type of plasmid maintenance function: postsegregational killing of plasmid-free cells". Proc. Natl. Acad. Sci. U.S.A. 83 (10): 3116–20. doi:10.1073/pnas.83.10.3116. PMC 323463. PMID 3517851. Retrieved 2010-08-10.
Toxin Fst, type I toxin-antitoxin system Provide feedback
Fst (faecalis plasmid stabilization toxin), also known as RNA I, is a toxic peptide. Its N-terminus forms a transmembrane alpha helix, its C terminus is disordered and is likely to be cytosolic. Its translation is inhibited by the antisense RNA, RNA II, which acts as an antitoxin [1,2].
Greenfield TJ, Weaver KE;, Mol Microbiol. 2000;37:661-670.: Antisense RNA regulation of the pAD1 par post-segregational killing system requires interaction at the 5' and 3' ends of the RNAs. PUBMED:10931359 EPMC:10931359
Gobl C, Kosol S, Stockner T, Ruckert HM, Zangger K;, Biochemistry. 2010;49:6567-6575.: Solution structure and membrane binding of the toxin fst of the par addiction module. PUBMED:20677831 EPMC:20677831
External database links
This tab holds annotation information from the InterPro database.
InterPro entry IPR025882
Fst (faecalis plasmid stabilisation toxin), also known as RNA I, is a toxic peptide. Its N terminus forms a transmembrane alpha helix, its C terminus is disordered and is likely to be cytosolic. Its translation is inhibited by the antisense RNA, RNA II, which acts as an antitoxin [PUBMED:10931359, PUBMED:20677831].
- the number of sequences which exhibit this architecture
a textual description of the architecture, e.g. Gla, EGF x 2, Trypsin.
This example describes an architecture with one
Gladomain, followed by two consecutive
EGFdomains, and finally a single
- the UniProt description of the protein sequence
- the number of residues in the sequence
- the Pfam graphic itself.
Loading domain graphics...
We make a range of alignments for each Pfam-A family:
- the curated alignment from which the HMM for the family is built
- the alignment generated by searching the sequence database using the HMM
- Representative Proteomes (RPs) at 15%, 35%, 55% and 75% co-membership thresholds
- alignment generated by searching the NCBI sequence database using the family HMM
- alignment generated by searching the metagenomics sequence database using the family HMM
You can see the alignments as HTML or in three different sequence viewers:
- Pfam viewer
- an HTML-based viewer that uses DAS to retrieve alignment fragments on request
1Cannot generate PP/Heatmap alignments for seeds; no PP data available
Key: available, not generated, — not available.
Format an alignment
If you find these logos useful in your own work, please consider citing the following article:
Note: You can also download the data file for the tree.
Curation and family details
|Number in seed:||13|
|Number in full:||45|
|Average length of the domain:||21.00 aa|
|Average identity of full alignment:||62 %|
|Average coverage of the sequence by the domain:||62.92 %|
|HMM build commands:||
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||1|
|Download:||download the raw HMM for this family|
Weight segments by...
Change the size of the sunburst
selected sequences to HMM
a FASTA-format file
- 0 sequences
- 0 species
How the sunburst is generated
Colouring and labels
Anomalies in the taxonomy tree
Missing taxonomic levels
Unmapped species names
Too many species/sequences
The tree shows the occurrence of this domain across different species. More...
You can use the tree controls to manipulate how the interactive tree is displayed:
- show/hide the summary boxes
- highlight species that are represented in the seed alignment
- expand/collapse the tree or expand it to a given depth
- select a sub-tree or a set of species within the tree and view them graphically or as an alignment
- save a plain text representation of the tree
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 Fst_toxin domain has been found. There are 1 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.
Loading structure mapping...