Molecular Biology of the Gene 7th Edition by Richard Losick, James Watson, Michael Levine, Tamara Baker, Alexander Gann

Exercise 4

Researchers want to find a way to confer antibiotic resistance to selected bacterial cells. To do so, they decide to identify a sequence of RNA (aptamer) by SELEX that specifically binds to the antibiotic of interest and expresses that RNA aptamer in the selected cells to confer antibiotic resistance.
A. Given what you know about RNA, hypothesize what general properties of the RNA aptamer allow for specific binding to the antibiotic.
B. Instead of using SELEX, the researchers could start with an isolated pool of RNAs encoded by the bacterial genome and select for the RNA(s) that bind the antibiotic to identify their desired RNA. Give two advantages of using SELEX rather than this method.