Viva Origino
Online ISSN : 1346-6933
Print ISSN : 0910-4003
Volume 32, Issue 3
Displaying 1-3 of 3 articles from this issue
  • Hajime Honda
    2004 Volume 32 Issue 3 Pages 152-154
    Published: 2004
    Released on J-STAGE: January 29, 2022
    JOURNAL FREE ACCESS

    It is indeed difficult to make a living things even a very primitive one. In spite of the difficulties, we have aspired to understand the origins of life in an experimental manner. Standing on the tons of knowledge brought about by preceding researchers, I wonder if it is possible to reconstruct a primitive type of life. In this review, a part of knowledge for prebiotic synthesis of poly-nucleotide will be firstly summarized by Hiroaki Sawai, then the aims of a recently started project entitled “Whole Cell Project” will be introduced from the view point of the origins of life by Seiki Kuramitsu, the project leader of the project. I hope this small review will be a signpost for the young scientist who is just beginning the research on the origins of life.

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  • Hiroaki Sawai
    2004 Volume 32 Issue 3 Pages 155-168
    Published: 2004
    Released on J-STAGE: January 29, 2022
    JOURNAL FREE ACCESS

      In the RNA world hypothesis of origin of life it is proposed that RNA could play the roles of information carrier and catalyst in an early life on primitive earth. RNA had to be formed during chemical evolution to realize the RNA world. In this article, I review approaches to the laboratory demonstration of prebiotic synthesis of RNA. Metal ion catalyst such as lead, zinc or uranyl ion works as a catalyst for polymerization of imizazole-activated mononucleotides in neutral aqueous solution or under eutechtic condition forming RNAs containing dimer to octadecamer. Montmorillonite clay also catlyzes the formation of RNA from the activated nucleotides forming the corresponding RNA with chain length from two to fourteen. Successive addition of the activated nucleotide to the montmorillonite catalyst resulted in chain-elongation of RNA as long as 50mer. The problem of the simulated model reactions of prebiotic synthesis of RNA will be also described.

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  • Seiki Kuramitsu
    2004 Volume 32 Issue 3 Pages 169-172
    Published: 2004
    Released on J-STAGE: January 29, 2022
    JOURNAL FREE ACCESS

      One of the long-range goals of structural and functional genomics is the interpretation of all fundamental biological phenomena at the atomic level. We expected to accomplish this by identifying the structure and function of all biological molecules making up the human body. However, Homo sapiens contains more than 30,000 proteins, and these proteins are rather unstable for structural and functional analyses. It is estimated that the minimum gene set essential for a free living organism is about 1,000. Microorganisms living in extreme environments often have approximately this number of genes. Therefore, in 1995(Kuramitsu et al. (1995) Protein Eng. 8, 964-964; Yokoyama et al. (2000) Nature Struct. Biol. 7, 943-945; http://www.thermos.org), we proposed that one such organism should be selected and an attempt made to understand the mechanisms of all the biological phenomena occurring in it by investigating the components’ molecular functions at the atomic level on the basis of their three-dimensional structures. The organism had to be selected on the basis of two criteria: (a) the organism has a “gene manipulating system”, and (b) it is “the most thermophilic” organism among organisms that meet criterion (a). These criteria led us to select the extreme thermophile Thermus thermophilus HB8, which is a Gram-negative eubacterium about 5 μm in length and capable of growing at 85℃. We named the project "The Structural and Functional Whole-Cell Project for Thermus thermophilus HB8." This project is intended to be carried out in four steps: (1) structural genomics step; (2) functional genomics step; (3) detailed analysis step of each molecule; and (4) system biology step (simulation of whole biological phenomena). This “Structural and Functional Whole-Cell Project” represents the first step toward the “atomic biology” of the 21st century, following on the heels of the “molecular biology” that characterized the 20th century.

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