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13  structures 41  species 0  interactions 162  sequences 3  architectures

Family: Cecropin (PF00272)

Summary: Cecropin family

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This is the Wikipedia entry entitled "Cecropin". More...

Cecropin Edit Wikipedia article

Cecropin family
2IGR ?
OPM superfamily151
OPM protein1d9j

Cecropins are antimicrobial peptides.[1][2] 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[3][4][5] 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 α helices.[6]:4.2 At low peptide to lipid ratios ion channels are formed, at high peptide to lipid ratios pores are formed.[7]
Cecropin B
Peptide Sequence (KWKVFKKIEKMGRNIRNGIVKAGPAIAVLGEAKAL). Secondary structure includes two α helices.[6]:4.2
from Aedes aegypti (Yellowfever mosquito).[8]
from Papilio xuthus (a butterfly) [8]
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.[9]

Some of the cecropins (e.g. cecropin A, and cecropin B) have anticancer properties and are called anticancer peptides (ACPs).[6]:3 Hybrid ACPs based on Cecropin A have been studied for anticancer properties.[6]:7.1


  1. ^ Cecropins at the US National Library of Medicine Medical Subject Headings (MeSH)
  2. ^ 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): 8973–83, doi:10.1074/jbc.M806778200, PMC 2659254, PMID 19176529.
  3. ^ Boman HG, Hultmark D (1987), "Cell-free immunity in insects", Annu. Rev. Microbiol., 41: 103–126, doi:10.1146/annurev.mi.41.100187.000535, PMID 3318666.
  4. ^ Boman HG (1991), "Antibacterial peptides: key components needed in immunity", Cell, 65 (2): 205–207, doi:10.1016/0092-8674(91)90154-Q, PMID 2015623.
  5. ^ 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): 23–31, doi:10.1111/j.1432-1033.1991.tb16252.x, PMID 1915368.
  6. ^ a b c d Hoskin, D.W.; Ramamoorthy, A. (February 2008), "Studies on anticancer activities of antimicrobial peptides", Biochimica et Biophysica Acta (BBA) - Biomembranes, 1778 (2): 357–375, doi:10.1016/j.bbamem.2007.11.008, PMC 2238813, PMID 18078805
  7. ^ Loraine Susan Silvestro, "Function and structure of cecropin A" (January 1, 2000). Dissertations available from ProQuest. Paper AAI9965567.
  8. ^ a b cecropin family OPM
  9. ^ Protein Data Bank (1930), Solution structure of CB1a, a novel anticancer peptide derived from natural antimicrobial peptide cecropin B [<> <Protein Data Bank>]

Further reading

  • Hoskin 2008 (above) section 4.2

External links

This page is based on a Wikipedia article. The text is available under the Creative Commons Attribution/Share-Alike License.

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.

Cecropin family Provide feedback

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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 ]

Gene Ontology

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Domain organisation

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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 (reference proteomes) using the family HMM. We also generate alignments using four representative proteomes (RP) sets and the UniProtKB sequence database. More...

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Curation and family details

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Seed source: Prosite
Previous IDs: cecropin;
Type: Family
Sequence Ontology: SO:0100021
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 %

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HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 61295632 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 25.0 25.0
Trusted cut-off 27.3 26.9
Noise cut-off 23.5 24.6
Model length: 30
Family (HMM) version: 22
Download: download the raw HMM for this family

Species distribution

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Archea Archea Eukaryota Eukaryota
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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