Designation of the two strands of DNA

From the JCBN/NC-IUB Newsletter 1989 [3]

Molecular biologists describing DNA sequences or referring to one of the two strands of double-stranded DNA frequently use complementary pairs of terms, such as coding/non-coding, sense/nonsense or transcribing/non-transcribing. Unfortunately none of these pairs is defined in a universally accepted way: for example, one may contrast 'the coding strand of DNA has the same sequence as mRNA' (page 723 in [1]) with 'coding strand: the strand of duplex DNA which is transcribed into a complementary mRNA molecule' (page 18 in [2]).

Of the three pairs of terms mentioned, NC-IUB and JCBN believe coding/non-coding to be preferable. Moreover, as the word 'coding' refers to the relationship between nucleic acids and proteins, rather than the mere transcription of DNA into RNA, it is logical to call the strand with the mRNA sequence the coding strand, as in the first example. When DNA sequences are described by giving the sequence of only one strand, this is usually the strand with the same sequence as the RNA (messenger, ribosomal, transfer, etc.) and should therefore be called the coding strand.

1. Lewin, B. (1987) Genes, John Wiley & Sons, New York.

2. Oliver, S. G. & Ward, J. M. (1985) A dictionary of genetic engineering, Cambridge University Press, Cambridge.

3.IUPAC-IUB Joint Commission on Biochemical Nomenclature (JCBN), and Nomenclature Commission of IUB (NC-IUB), Newsletter 1989, Arch. Biochem. Biophys., 1989, 272, 262-266; Biochem. Internat., 1989, 20, 209-214; Bioch. J., 1989, 265, I-IV; Biol. Chem. Hoppe-Seyler, 1989, 370, 1153-1156; Eur. J. Biochem., 1989, 183, 1-4.

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