Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

A working hypothesis on the interdependent genesis of nucleotide bases, protein amino acids, and primitive genetic code


In the course of experimental approach to the chemical evolution in the primeval sea, we have found that the main products from formaldehyde and hydroxylamine are glycine, alanine, serine, aspartic acid etc., and the products from glycine and formaldehyde are serine and aspartic acid. Guanine is found in the two-letter genetic codons of all these amino acids.

Based upon the finding and taking into consideration the probable synthetic pathways of nucleotide bases and protein amino acids in the course of chemical evolution and a correlation between the two-letter codons and the number of carbon atoms in the carbon skeleton of amino acids, 1 have been led to a working hypothesis on the interdependent genesis of nucleotide bases, protein amino acids, and primitive genetic code as shown in Table I.

Protein amino acids can be classified into two groups: Purine Group amino acids and Pyrimidine Group amino acids. Purine bases and Pyrimidine bases are predominant in two-letter codons of amino acids belonging to the former and the latter group respectively.

Guanine, adenine, and amino acids of the Purine Group may be regarded as synthesized from C1 and C2 compounds and N1 compounds (including C1N1 compunds such as HCN), probably through glycine, in the early stage of chemical evolution.

Uracil, cytosine, and amino acids of the Pyrimidine Group may be regarded as synthesized directly or indirectly from three-carbon chain compounds. This synthesis became possible after the accumulation of three-carbon chain compounds and their derivatives in the primeval sea.

The Purine Group can be further classified into a Guanine or (Gly+nC1) Subgroup and an Adenine or (Gly+nC2) Subgroup or simply nC2 Subgroup. The Pyrimidine Group can be further classified into a Uracil or C3C6C9 Subgroup and a Cytosine or C5-chain Subgroup (Table I).

It is suggested that the primitive genetic code was established by a specific interaction between amino acids and their respective nucleotide bases. The interaction was dependent upon their concentration in the primeval environments and the binding constants between amino acids and their respective bases.

This is a preview of subscription content, log in to check access.


  1. Crick, F. H. C.: 1968,J. Mol. Biol. 38, 367.

  2. Dillon, L. S.: 1973,Botanical Review 39, 301.

  3. Dillon, L. S.: 1978,The Genetic Mechanism and The Origin of Life, Plenum Press, New York and London, pp. 216–230.

  4. Egami, F.: 1979a,Kagaku (Science, Tokyo),49, 527.

  5. Egami, F.: 1979b,Nippon Nôgeikagaku Kaishi (J. Agr. Chem. Soc. Jpn) 53, 173.

  6. Ferris, J. P., Zamek, O. S., Altbuch, A. M., and Freiman, H.: 1974,J. Mol. Evol. 3, 301.

  7. Hatanaka, H., and Egami, F.: 1977,Bull. Chem. Soc. Jpn. 50, 1147.

  8. Jukes, T. H.: 1978,Adv. Enzym. ed. by A. Meister,47, 375.

  9. Jungck, J. R.: 1978,J. Mol. Evol. 11, 211.

  10. Kamaluddin, Yanagawa, H., and Egami, F.: 1979,J. Biochem. (Tokyo) 85, 1503.

  11. Lacey, J. C. and Pruitt, K. M.: 1969,Nature 223, 799.

  12. Mikelsaar, H. N.: 1975,J. Theor. Biol. 50, 203.

  13. Ochiai, T., Hatanaka, H., Ventilla, M., Yanagawa, H., Ogawa, Y., and Egami, F.: 1978, in H. Noda (ed.),Origin of Life, Proc. 5th Intern. Cong. Origin of Life, Center Acad. Publ. Jpn. pp. 135–139.

  14. Oró, J.: 1961,Nature 191, 1193.

  15. Sanchez, R. A., Ferris, J. P., and Orgel, L. E.: 1966,Science 153, 72.

  16. Sato, M., Okawa, K., and Akabori, S.: 1957,Bull. Chem. Soc. Jpn. 30, 937.

  17. Saxinger, C. and Ponnamperuma, C.: 1974,Origins of Life 5, 190.

  18. Shimizu, M.: 1979,Astrophys. Space Sci. 62, 509.

  19. Weber, A. L. and Lacey, J. C.: 1978,J. Mol. Evol. 11, 199.

  20. Woese, C. R.: 1967,The Genetic Code. The Mol. Basis for Gen. Exp., Harper and Row. Publ., New York, Evanston, and London.

  21. Woese, C.R., Dugre, D. H., Saxinger, W. C., and Dugre, S. A.: 1966,Proc. Nat. Acad. Sci. USA 55, 966.

  22. Yčas, M.: 1969,The Biological Code, North-Holland Publ., Amsterdam.

Download references

Author information

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Egami, F. A working hypothesis on the interdependent genesis of nucleotide bases, protein amino acids, and primitive genetic code. Origins Life Evol Biosphere 11, 197–202 (1981).

Download citation


  • Pyrimidine
  • Cytosine
  • Guanine
  • Aspartic Acid
  • Uracil