Amino Acid Frequency

This page to generate a frequency distribution of amino acids occuring at a particular numbered position, based on pre-calculated numbering stored in the database

• Use the Numbering Scheme dropdown to select a numbering scheme: Chothia, Martin or Kabat. The numbering schemes are explained in the help for the About / Definitions page.
• Use the Chain Type dropdown to select either the Heavy or the Light chain.
• Optionally, use the Organism dropdown to restrict the analysis to chains for a particular organism. If no organism is selected, frequencies will be calculated across all sequence in the database.
• Use the Position dropdown to select a numbered position for analysis.

A bar chart of the residue distribution for the selected residue is displayed together with an associated table containing the residue counts in non-identical sequences and the relative frequencies. You may also download a version of the graph.

Note The organism specification is hierarchical e.g. if you select Rattus the distribution will include sequences from all Rattus species including, for example, Rattus rattus and Rattus fuscipes.