Protein sequences are often compared by doing a global sequence alignment, where the sequences are lined up so that they have the largest number of matching characters. This Demonstration allows you to show the global alignment of two protein sequences on an alignment wheel, where wedges emanating from the center of the wheel indicate regions that match (in blue) and regions that do not match (in red). The sequences are shown running around the edge of the wheel, starting at the three o'clock position, with dashes indicating a deletion or insertion in the alignment. Select two proteins from the drop-down lists to see the alignment wheel comparing their amino acid sequences. Use the protein group drop-downs to choose protein groups of interest.