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4 Riboswitches and the RNA World
Abstract
The initial descriptions of engineered aptamers were striking for two reasons. First, they provided fresh demonstrations that nucleic acids could be subjected to Darwinian evolution in a test tube. Second, these along with the many reports that followed helped prove that nucleic acids have an enormous untapped potential for forming complex shapes, and that many different molecules could be selectively recognized by RNA and DNA (Gold et al. 1995; Osborne and Ellington 1997). Furthermore, these findings fit well with more robust versions of the RNA World theory (Woese 1967; Crick 1968; Orgel 1968; Gilbert 1986), which holds that aptamers might have existed alongside a diversity of ribozymes to allow early life forms to attain a complex metabolic state long before proteins had emerged (Benner et al. 1989; Hirao and Ellington 1995).
The recent discoveries of riboswitches in bacteria that selectively respond to fundamental metabolites provide researchers...
DOI: http://dx.doi.org/10.1101/0.89-107