This XML schema defines basic, reusable sequence related entities. For complete documentation, see http://www.pharmgkb.org/schema/. A DNA sequence. The valid sequence alphabet is A, T, C, and G. An IUPAC DNA sequence. The valid sequence alphabet is A, T, C, G and the IUPAC ambiguity codes. See http://www.ncbi.nlm.nih.gov/SNP/iupac.html for a list of the IUPAC ambiguity codes and their definitions. A variant DNA sequence. The valid sequence alphabet is A, T, C, G, and - (to denote a deletion). An RNA sequence. The valid sequence alphabet is A, U, C, and G. A protein sequence. The valid sequence alphabet is the IUB-IUPAC amino acid symbols. See http://www.chem.qmul.ac.uk/iupac/AminoAcid/A2021.html for the recommendation. An amino acid. This class defines a region of a sequence. See http://www.pharmgkb.org/schema/docs/region.html for details. The startPosition must be less than the stopPosition The startPosition must be less than the stopPosition The startPosition must be less than the stopPosition The startPosition must be less than the stopPosition The startPosition must be less than the stopPosition The startPosition must be less than the stopPosition The startPosition must be less than the stopPosition This class defines the coordinate system. See http://www.pharmgkb.org/schema/docs/coordinateSystem.html for details.