Cyclotides - Cyclotide Structure

Cyclotide Structure

Cyclotides have a well-defined three-dimensional structure as a result of their interlocking disulfide bonds and cyclic peptide backbone. Backbone loops and selected residues are labeled on the structure to help orientation. The amino acid sequence (single letter amino acid representation) for this peptide is indicated on the sequence diagram to the right. One of the interesting features of cyclic peptides is that knowledge of the peptide sequence does not reveal the ancestral head and tail; knowledge of the gene sequence is required for this. In the case of kalata B1 the indicated glycine (G) and asparagine (N) amino acids are the terminal residues that are linked in a peptide bond to cyclise the peptide.