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Articles tagged: pyrrolysine
Posted by Ville Koskinen (August 28, 2026)
Ambiguity residues B, X, Z and custom residues J, O, U
Mascot uses the IUPAC one-letter code for protein and peptide sequences. The 20 standard amino acids are encoded using the uppercase Latin letters ACDEFGHIKLMNPQRSTVWY. The remaining letters – B, J, O, U, X, Z – are also supported by Mascot and have a special meaning. Ambiguity residues B, X, Z The IUPAC one-letter symbols B, X and Z encode ambiguity: [...]