Amino Acid Periodicity (AAP)

This database contains information on all the different types of single amino acid periodicities observed in proteins of known three-dimensional structures in the PDB. For instance, a leucine repeated at every 7th position 3 times represents leucine periodicity with repeat interval 7 and repeat number 3. All proteins in the PDB characterized by this type of leucine repeat can be retrieved. This is possible from a representative dataset of proteins in the PDB or the entire PDB dataset or also the annotated sequences available in UniProt. Likewise, the database can be queried for the twenty different amino acid residues and for different repeat intervals or repeat numbers, in order to obtain the corresponding ‘hits’ in the database. Alternatively, any protein sequence can be pasted and the database would identify the different amino acid periodicity (AAP) types that are observed.