This paper gives the formulae for the Fourier transforms of a number of helical structures, and provides evidence that the structure of a synthetic polypeptide was based on the alpha helix of Pauling and Corey. "It was, I believe, the first fairly conclusive experimental evidence for the existence of a helical structure at the molecular level.... The value of this work, seen in retrospect, is that it was a first step on the road to the discovery of the structure of DNA by Jim Watson and Crick" (Cochran, "This week's citation classic," Current Contents, May 18, 1987, 16).

Watson and Crick shared the Nobel Prize with M. H. F. Wilkins (No. 256.4) "for their discoveries concerning the molecular structure of nucleic acids and its significance for information transfer in living material." Later they proposed how DNA might explain the chemical mechanism by which cells passed on their character accurately. See No. 7138.

The journal Nature later published an "early draft" of the Watson & Crick paper with differing text and extensive explanatory annotations. It is available from exploratorium.edu at this link.

In this paper published on May 30, 1953 Watson and Crick proposed the method of replication of DNA. This discovery has been called as significant, or possibly even more significant, than their discovery of the double-helical structure of DNA published in April 1953. 

Rich and Crick solved the structure of collagen, the main structural protein in the extracellular matrix found in the body's various connective tissues. As the main component of connective tissue, it is the most abundant protein in mammals, making up from 25% to 35% of the whole-body protein content. Collagen consists of amino acids bound together to form a triple helix of elongated fibril known as a collagen helix. 
See also:
Rich, Alexander - Crick, Francis H.C. The Structure of Collagen. 1957. Offprint from "Recent Advances in Gelatin and Glue Research" (Pergamon Press: London, 1957), the Proceedings of a Conference sponsored by the British Gelatine and Glue Research Association and held at the University of Cambridge, 1-5 July 1957, pp. 20-24.

This paper published in September 1957, based on Crick's famous "Central Dogma" lecture given the same month, presented his first published statement of The Central Dogma: “Information is transmitted from DNA and RNA to proteins, but information cannot flow from a protein to DNA. See GM 6895.  

This paper proposed two general principles: 1) The Sequence Hypothesis: “The order of bases in a portion of DNA represents a code for the amino acid sequence of a specific protein. Each ‘word’ in the code would name a specific amino acid. From the two dimensional genetic text, written in DNA, are forced the whole diversity of uniquely shaped three-dimensional proteins” , and 2) The Central Dogma: “Information is transmitted from DNA and RNA to proteins, but information cannot flow from a protein to DNA. This paper “permanently altered the logic of biology” (Judson). 

Crick's first published statement of The Central Dogma appeared in the September 1957 issue  of Scientific American, 197, No. 3, 188-203, based upon his famous "Central Dogma" lecture given in September 1957 (G-M 13097). 

The codons in DNA specifying amino acids in proteins. 

"In the genetic code, there are 4³ = 64 possible codons (3 nucleotide sequences). For translation, each of these codons requires a tRNA molecule with an anticodon with which it can stably complement. If each tRNA molecule is paired with its complementary mRNA codon using canonical Watson-Crick base pairing, then 64 types of tRNA molecule would be required. In the standard genetic code, three of these 64 mRNA codons (UAA, UAG and UGA) are stop codons. These terminate translation by binding to release factors rather than tRNA molecules, so canonical pairing would require 61 species of tRNA. Since most organisms have fewer than 45 types of tRNA, ⁣some tRNA types can pair with multiple, synonymous codons, all of which encode the same amino acid. In 1966, Francis Crick proposed the Wobble Hypothesis to account for this. He postulated that the 5' base on the anticodon, which binds to the 3' base on the mRNA, was not as spatially confined as the other two bases and could, thus, have non-standard base pairing. Crick creatively named it for the small amount of "play" or wobble that occurs at this third codon position. Movement ("wobble") of the base in the 5' anticodon position is necessary for small conformational adjustments that affect the overall pairing geometry of anticodons of tRNA" (Wikipedia article on Wobble base pair, accessed 7-22).