Watson and Crick (Nobel 1962) Watson
   and Crick proposed the double-helix structure of DNA in 1953.

   Each  turn of the helix contains 10 nucleotides^*, so the 3.4 angstrom
   (0.34  nm)  internucleotide  distance add up to 34 angstroms per turn,
   twisting around major and minor grooves.