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Journal of Biosciences

, Volume 27, Issue 2, pp 165–186 | Cite as

Origins of gene, genetic code, protein and life: comprehensive view of life systems from a GNC-SNS primitive genetic code hypothesis

  • K. Ikehara
Review

Abstract

We have investigated the origin of genes, the genetic code, proteins and life using six indices (hydropathy, α-helix, β-sheet and β-turn formabilities, acidic amino acid content and basic amino acid content) necessary for appropriate three-dimensional structure formation of globular proteins. From the analysis of microbial genes, we have concluded that newly-born genes are products of nonstop frames (NSF) on antisense strands of microbial GC-rich genes [GC-NSF(a)] and from SNS repeating sequences [(SNS)n] similar to the GC-NSF(a) (S and N mean G or C and either of four bases, respectively). We have also proposed that the universal genetic code used by most organisms on the earth presently could be derived from a GNC-SNS primitive genetic code. We have further presented the [GADV]-protein world hypothesis of the origin of life as well as a hypothesis of protein production, suggesting that proteins were originally produced by random peptide formation of amino acids restricted in specific amino acid compositions termed as GNC-, SNS and GC-NSF(a)-0th order structures of proteins. The [GADV]-protein world hypothesis is primarily derived from the GNC-primitive genetic code hypothesis. It is also expected that basic properties of extant genes and proteins could be revealed by considerations based on the scenario with four stages

Keywords

GNC-SNS primitive genetic code hypothesis origin of genes origin of genetic code origin of life origin of proteins 

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Copyright information

© Indian Academy of Sciences 2002

Authors and Affiliations

  • K. Ikehara
    • 1
  1. 1.Department of Chemistry, Faculty of ScienceNara Women’s UniversityNaraJapan

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