Summary: Cecropin family
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Cecropin Edit Wikipedia article
|SCOPe||1f0d / SUPFAM|
Cecropins are antimicrobial peptides. They were first isolated from the hemolymph of Hyalophora cecropia, whence the term cecropin was derived. Cecropins lyse bacterial cell membranes; they also inhibit proline uptake and cause leaky membranes.
Cecropins constitute a main part of the innate immune system of insects. Cecropins are small proteins anywhere from 31 - 37 amino acids long and are active against both Gram-positive and Gram-negative bacteria. Cecropins isolated from insects other than Hyalophora cecropia (Cecropia moth) have been given various names; bactericidin, lepidopterin, sarcotoxin, etc. All of these are structurally related
Members include :
- Cecropin A
- Peptide Sequence (KWKLFKKIEKVGQNIRDGIIKAGPAVAVVGQATQIAK). Secondary structure includes two Î± helices.:4.2 At low peptide to lipid ratios ion channels are formed, at high peptide to lipid ratios pores are formed.
- Cecropin B
- Peptide Sequence (KWKVFKKIEKMGRNIRNGIVKAGPAIAVLGEAKAL). Secondary structure includes two Î± helices.:4.2
- Cecropin P1
- Peptide Sequence (SWLSKTAKKLENSAKKRISEGIAIAIQGGPR). An antibacterial peptide from Ascaris suum, a parasitic nematode that resides in the pig intestine, also belongs to this family.
A derivative of Cecropin B is an anticancer polypeptide(L). Structure consists of mainly alpha helixes, determined by solution NMR. Protein molecular weight = 4203.4g/mol.
Some of the cecropins (e.g. cecropin A, and cecropin B) have anticancer properties and are called anticancer peptides (ACPs).:3 Hybrid ACPs based on Cecropin A have been studied for anticancer properties.:7.1
- Cecropins at the US National Library of Medicine Medical Subject Headings (MeSH)
- Lauwers A, Twyffels L, Soin R, Wauquier C, Kruys V, Gueydan C (January 2009), "Post-transcriptional regulation of genes encoding anti-microbial peptides in Drosophila", J. Biol. Chem., 284 (13): 8973â€“83, doi:10.1074/jbc.M806778200, PMC 2659254, PMID 19176529.
- Boman HG, Hultmark D (1987), "Cell-free immunity in insects", Annu. Rev. Microbiol., 41: 103â€“126, doi:10.1146/annurev.mi.41.100187.000535, PMID 3318666.
- Boman HG (1991), "Antibacterial peptides: key components needed in immunity", Cell, 65 (2): 205â€“207, doi:10.1016/0092-8674(91)90154-Q, PMID 2015623.
- Boman HG, Faye I, Lee JY, Gudmundsson GH, Lidholm DA (1991), "Cell-free immunity in Cecropia. A model system for antibacterial proteins", Eur. J. Biochem., 201 (1): 23â€“31, doi:10.1111/j.1432-1033.1991.tb16252.x, PMID 1915368.
- Hoskin, D.W.; Ramamoorthy, A. (February 2008), "Studies on anticancer activities of antimicrobial peptides", Biochimica et Biophysica Acta (BBA) - Biomembranes, 1778 (2): 357â€“375, doi:10.1016/j.bbamem.2007.11.008, PMC 2238813, PMID 18078805
- Loraine Susan Silvestro, "Function and structure of cecropin A" (January 1, 2000). Dissertations available from ProQuest. Paper AAI9965567. http://repository.upenn.edu/dissertations/AAI9965567
- cecropin family OPM
- Protein Data Bank (1930), Solution structure of CB1a, a novel anticancer peptide derived from natural antimicrobial peptide cecropin B [<http://www.rcsb.org/pdb/explore/explore.do?structureId=2IGR> <Protein Data Bank>]
- Hoskin 2008 (above) section 4.2
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External database links
This tab holds annotation information from the InterPro database.
InterPro entry IPR000875
Cecropins [ PUBMED:3318666 , PUBMED:2015623 , PUBMED:1915368 ] are potent antibacterial proteins that constitute a main part of the cell-free immunity of insects. Cecropins are small proteins of about 35 amino acid residues active against both Gram-positive and Gram-negative bacteria. They seem to exert a lytic action on bacterial membranes. Cecropins have been given various names, including bactericidin, lepidopteran and sarcotoxin. All of these peptides are structurally related.This entry also includes the antibacterial protein andropin. The andropin gene is closely linked to the cecropin gene cluster of Drosophila melanogaster [ PUBMED:11965438 , PUBMED:1899226 ]
The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.
|Cellular component||extracellular region (GO:0005576)|
|Biological process||antibacterial humoral response (GO:0019731)|
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1Cannot generate PP/Heatmap alignments for seeds; no PP data available
Key: available, not generated, — not available.
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|Author:||Finn RD , Bateman A|
|Number in seed:||21|
|Number in full:||162|
|Average length of the domain:||30.10 aa|
|Average identity of full alignment:||44 %|
|Average coverage of the sequence by the domain:||44.25 %|
|HMM build commands:||
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 61295632 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||22|
|Download:||download the raw HMM for this family|
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How the sunburst is generated
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The tree is built by looking at each sequence in the full alignment for the family. We take the name of the species given by UniProt and try to map that to the full taxonomic tree from NCBI. In some cases, the name chosen by UniProt does not map to any node in the NCBI tree, perhaps because the chosen name is listed as a synonym or a misspelling in the NCBI taxonomy.
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Since we reduce the species tree to only the eight main taxonomic levels, sequences that are mapped to the sub-species level in the tree would not normally be shown. Rather than leave out these species, we map them instead to their parent species. So, for example, for sequences belonging to one of the Vibrio cholerae sub-species in the NCBI taxonomy, we show them instead as belonging to the species Vibrio cholerae.
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The tree shows the occurrence of this domain across different species. More...
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For all of the domain matches in a full alignment, we count the number that are found on all sequences in the alignment. This total is shown in the purple box.
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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 Cecropin domain has been found. There are 13 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 sequence.
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AlphaFold Structure Predictions
The list of proteins below match this family and have AlphaFold predicted structures. Click on the protein accession to view the predicted structure.
|Protein||Predicted structure||External Information|
|C0HKQ7||View 3D Structure||Click here|
|C0HKQ8||View 3D Structure||Click here|
|O16829||View 3D Structure||Click here|
|P14956||View 3D Structure||Click here|
|P21663||View 3D Structure||Click here|