The amino acid represented by the single-letter abbreviation "Q" is Glutamine.
According to the reference (Amino Acids www.vanderbilt.edu › AnS › Chemistry › Rizzo › stuff › AminoAcids), the relationship between the amino acid, its abbreviation and single letter code is as follows:
| Amino Acid | Abbreviation | Single Letter Code |
|---|---|---|
| Glutamine | Gln | Q |
