Forty years under the central dogma.

The Central Dogma. This states that once 'information' has passed into protein it cannot get out again. In more detail, the transfer of information from nucleic acid to protein may be possible, but transfer from protein to protein, or from protein to nucleic acid is impossible. Information means here the precise determination of sequence, either of bases in the nucleic acid or of amino-acid residues in the protein 1. The quotation above is from a seminal paper, 'On Protein Synthesis,' presented by Francis Crick at the 1957 annual meeting of the Society of Experimental Biology and published in 1958 1. In this paper, Crick listed the standard set of 20 amino acid residues for the first time; argued that 'the specificity of a piece of nucleic acid is expressed solely by the sequence of its bases, and that this sequence is a (simple) code for the amino acid sequence of a particular protein'; argued that the three-dimensional con-formation of a protein must be determined by its amino acid sequence; pointed out that protein synthesis must be sequential; and presented his hypothesis of 'adaptor' molecules mediating protein formation at the ribosome. Most importantly, Crick formulated what he called the 'Central Dogma', which is the focus of this article. The Central Dogma had and still has an influential place in molecular biology. It has been a constant point of reference that served as a distinctive icon for proponents of the new molecular biology of the late 1950s and 1960s. However, it has also provided a target for many criticisms of the molecular approach. In this article, we give a short overview of the history of the Central Dogma, in the hope of stimulating further reflection and analysis.