"Is there any astrological thing that will happen in 16 June 2013, or any information of a disaster that will take place at that time? "
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A Self-assembling Collectively Autocatalytic Set of RNA Oligomers
PI: Lehman, Niles
The origins of life required the advent of biological information. Such information could exist in a pool of short linear polymers, such as RNA oligomers synthesized abiotically. We propose to demonstrate that self-replicating RNA molecules can emerge spontaneously via the aggregation of a collectively autocatalytic set found within a pool of random RNA oligomers, each 40 nucleotides or less in length. This would be an empirical demonstration of the ideas proposed by Stuart Kauffman regarding emergence of order from chaos. Our approach is to exploit the intrinsic ability of some RNAs to recombine other RNAs to produce new combinations of sequences.
In publications and preliminary data we have demonstrated that the Azoarcus ribozyme, 198 nucleotides in length, can be fragmented into four pieces that can spontaneously self-assemble into a covalently-contiguous molecule through recombination reactions. These assemblages can self-replicate because they can autocatalytically catalyze further self-assembly reactions. In the current proposal we will extend this methodology by exploring whether smaller and more random fragments in a pool of oligomers can accomplish the same task.
We propose three sets experiments to achieve this goal. The first is to break the current Azoarcus RNA system into five or more fragments, such that the average fragment length drops below 40 nucleotides. The second is to select for a shorter version of the Azoarcus ribozyme by deleting large sections of the molecule, targeting a recombinase that is less than 140 nucleotides. The third is to use a novel type of in vitro selection, termed autocatalytic enrichment selection, to bring a pool of RNA oligomers which does not demonstrate detectable self-assembly back across a complexity threshold to the point where it does self-assemble and self-replicate. We can accomplish these experiments inexpensively with graduate and undergraduate students at Portland State University in three years’ time.
