The precursor sequences of a number of antimicrobial peptides secreted by neutrophils (polymorphonuclear leukocytes) upon activation have been found to be evolutionarily related and are collectively known as cathelicidins [PMID: 7589491].
Structurally, these proteins consist of three domains: a signal sequence, a conserved region of about 100 residues that contains four cysteines involved in two disulphide bonds, and a highly divergent C-terminal section of variable size. It is in this C-terminal section that the antibacterial peptides are found; they are proteolytically processed from their precursor by enzymes such as elastase.
Note:
The format for Signature ID is the family name, followed by H or P for HMM or Pattern respectively. The integer suffixed to H or P denotes the length of the sequences used to create the family signature. If no integer is suffixed, it indicates that the signature was created using all the sequences of the family. The integer following the underscore denotes the number of sequences used for the creation of signatures.
For example:
AureinH_21 is a HMM for Aurein family created using 21 sequences.
AureinP16_9 is a pattern for Aurein family derived using 9 input sequences that are 16 residues long.
