How should ambiguity symbols be used in amino acid sequences?

The use of ambiguity symbols in amino acid sequences is addressed in MPEP 2412.05(d). Here are the key points:

• Ambiguity symbols are used when an amino acid in a sequence is not clearly identified.
• The MPEP states: “The symbol “Xaa” or “X” should be used for an unknown or other amino acid.“
• When “X” is used, it must be further defined in the Feature section of the sequence listing.
• The feature key “VARIANT” should be used, along with the possible amino acids as qualifier values.

Using these symbols correctly is crucial for accurately representing uncertainty in amino acid sequences while maintaining the integrity of the sequence listing.

To learn more:

• ambiguity symbols
• amino acid sequences
• Xaa
• X
• VARIANT