History of genetics code for specific proteins, leading to the "one gene, one enzyme" hypothesis. Oswald Avery, Colin Munro MacLeod, and Maclyn McCarty showed in 1944 that DNA holds the gene's information. In 1952, Rosalind Franklin and Raymond Gosling produced a strikingly clear x-ray diffraction pattern indicating a helical form, and in 1953, James D. Watson and Francis Crick demonstrated the molecular structure of DNA. Together, these discoveries established the central dogma of molecular biology, which states that proteins are translated from RNA which is transcribed by DNA. This dogma has since been shown to have exceptions, such as reverse transcription in retroviruses.
Francis Crick the protein alpha helix a few years earlier. The Watson and Crick discovery of the DNA double helix structure was made possible by their willingness to combine theory, modelling and experimental results (albeit mostly done by others) to achieve their goal. The DNA double helix structure proposed by Watson and Crick was based upon "Watson-Crick" bonds between the four bases most frequently found in DNA (A, C, T, G) and RNA (A, C, U, G). However, later research showed that triple-stranded, quadruple-stranded and other more complex DNA molecular structures required Hoogsteen base pairing. The entire field of synthetic biology began