scholarly journals On Francis Crick, the genetic code, and a clever kid

2018 ◽  
Vol 28 (7) ◽  
pp. R305
Author(s):  
Bob Goldstein
Keyword(s):  
Author(s):  
Eugene Koonin

Nearly 50 years ago, Francis Crick propounded the frozen accident scenario for the evolution of the genetic code along with the hypothesis that the early translation system consisted primarily of RNA. Under the frozen accident perspective, the code is universal among modern life forms because any change in codon assignment would be highly deleterious. The frozen accident can be considered the default theory of code evolution because it does not imply any specific interactions between amino acids and the cognate codons or anticodons, or any particular properties of the code. The subsequent 49 years of code studies have elucidated notable features of the standard code, such as high robustness to errors, but failed to develop a compelling explanation for codon assignments. In particular, stereochemical affinity between amino acids and the cognate codons or anticodons does not seem to account for the origin and evolution of the code. Here I expand Crick’s hypothesis on RNA-only translation system by presenting evidence that this early translation already attained high fidelity that allowed protein evolution. I outline an experimentally testable scenario for the evolution of the code that combines a distinct version of the stereochemical hypothesis, in which amino acids are recognized via unique sites in the tertiary structure of proto-tRNAs, rather than by anticodons, expansion of the code via proto-tRNA duplication and the frozen accident.


2004 ◽  
Vol 48 (2) ◽  
pp. 245-260
Author(s):  
Chris Beckett

“This is an historic occasion”, announced Francis Crick on 2 June 1966, as he began the opening address of the annual meeting of molecular biologists at Cold Spring Harbor. “There have been many meetings”, he continued, “about the genetic code during the past ten or twelve years but this is the first important one to be held since the code became known.” Such bold pronouncements usually guarantee that an occasion will linger in history's footnotes and never shine centre-page. But, as the first public presentation of the complete genetic code, the moment had some claim to being historically complementary to the publication of James Watson and Crick's first paper in Nature. In April 1953, in fourteen paragraphs and a diagrammatic sketch (contributed by Odile Crick), they had announced—with a minimalism that came more of urgent certainty than of diffidence or reticence—not just a physical structure for DNA, but something far more. “It has not escaped our notice that the specific pairing [of purine and pyrimidine bases] we have postulated immediately suggests a possible copying mechanism for the genetic material.” The trajectory begun in 1953 with the suggestion of “a possible copying mechanism” completed its public arc at Cold Spring Harbor in 1966 with a very specific and (almost) complete table showing the genetic code. The occasion “marked”, as Crick later judged, “the end of classical molecular biology”.


2007 ◽  
Vol 117 (3) ◽  
pp. 513-513
Author(s):  
Charles Stevens
Keyword(s):  

Genetics ◽  
2019 ◽  
Vol 211 (3) ◽  
pp. 789-795
Author(s):  
Bernard S. Strauss

Between about 1951 and the early 1960s, the basic structure of molecular biology was revealed. Central to our understanding was the unraveling of the various roles of RNA, culminating in the identification of messenger RNA (mRNA) and the deciphering of the genetic code. We know a great deal about the role of Brenner, Crick, Jacob, and Nirenberg in these discoveries, but many others played important supporting parts. One of these is a little-known scientist, Martynas Yčas, who appears in histories, generally without explanation, as the “archivist of the RNA Tie Club.” Yčas was born in Lithuania. His father helped write the Lithuanian Constitution in 1919. He studied Roman Law and served in the Lithuanian army before escaping from the Russians in 1940. The records of correspondence of Yčas with the physicist George Gamow and with Francis Crick throw some light on the genesis of our understanding of the role of mRNA. The story of the “RNA Tie Club” illustrates the difficulty in assigning credit for important discoveries and underscores the importance of a free exchange of information, even (or especially) among competitors.


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