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标题：The stability of the RNA bases: Implications for the origin of life
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作者：Matthew Levy ; Stanley L. Miller
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1998
卷号：95
期号：14
页码：7933-7938
DOI：10.1073/pnas.95.14.7933
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：High-temperature origin-of-life theories require that the components of the first genetic material are stable. We therefore have measured the half-lives for the decomposition of the nucleobases. They have been found to be short on the geologic time scale. At 100{degrees}C, the growth temperatures of the hyperthermophiles, the half-lives are too short to allow for the adequate accumulation of these compounds (t1/2 for A and G {approx} 1 yr; U = 12 yr; C = 19 days). Therefore, unless the origin of life took place extremely rapidly (<100 yr), we conclude that a high-temperature origin of life may be possible, but it cannot involve adenine, uracil, guanine, or cytosine. The rates of hydrolysis at 100{degrees}C also suggest that an ocean-boiling asteroid impact would reset the prebiotic clock, requiring prebiotic synthetic processes to begin again. At 0{degrees}C, A, U, G, and T appear to be sufficiently stable (t1/2 [≥] 106 yr) to be involved in a low-temperature origin of life. However, the lack of stability of cytosine at 0{degrees}C (t1/2 = 17,000 yr) raises the possibility that the GC base pair may not have been used in the first genetic material unless life arose quickly (<106 yr) after a sterilization event. A two-letter code or an alternative base pair may have been used instead.
关键词：nucleobase hydrolysis/RNA world/chemical evolution