RNA Quotes (5 quotes)
Recently, we’ve reported that we have made all five bases, the compounds that spell out the instructions for all life and are a part of the nucleic acids, RNA and DNA. Not only did we make all five bases but we found them in a meteorite! So that these two things coming together really assure us that the molecules necessary for life can be found in the absence of life. This was the biggest stumbling block.
The essential molecule of reproduction, DNA, … is composed of only four nitrogen bases (adenine, thymine, guanine, and cytosine), the sugar deoxyribose, and a phosphate. DNA’s intermediary, RNA, differs only by the substitution of the sugar ribose for deoxyribose and the nitrogen base uracil for thymine. The proteins of living organisms are made with a mere 20 amino acids, all arranged in a “left-handed” configuration. Taking into account all 28 building blocks, or “letters” (20 amino acids, five bases, two sugars, and one phosphate), the message is clear: With such a limited alphabet, all life must have had a common chemical origin.
The notion that individualism came first runs against the very grain of cosmic history. … grouping has been inherent in evolution since the first quarks joined to form neutrons and protons. Similarly, replicators—RNA, DNA, and genes—have always worked in teams… The bacteria of 3.5 billion years ago were creatures of the crowd. So were the trilobites and echinoderms of the Cambrian age.
These results demonstrate that there is a new polymerase inside the virions of RNA tumour viruses. It is not present in supernatents of normal cells but is present in virions of avian sarcoma and leukemia RNA tumour viruses. The polymerase seems to catalyse the incorporation of deoxyrinonucleotide triphosphates into DNA from an RNA template. Work is being performed to characterize further the reaction and the product. If the present results and Baltimore's results with Rauscher leukemia virus are upheld, they will constitute strong evidence that the DNA proviruses have a DNA genome when they are in virions. This result would have strong implications for theories of viral carcinogenesis and, possibly, for theories of information transfer in other biological systems. [Co-author with American virologist Satoshi Mizutani]
We should first look at the evidence that DNA itself is not the direct template that orders amino acid sequences. Instead, the genetic information of DNA is transferred to another class of molecules which then serve as the protein templates. These intermediate templates are molecules of ribonucleic acid (RNA), large polymeric molecules chemically very similar to DNA. Their relation to DNA and protein is usually summarized by the central dogma, a How scheme for genetic information first proposed some twenty years ago.