Patent ID: 7081341

Claim:
A method for identifying drug candidates comprising: (a) transforming a first set of host cells with a first set of plasmids, each plasmid comprising a first mutant rRNA gene and a first selectable marker gene; wherein said mutant rRNA gene comprises at least one mutation and a first mutant Anti-Shine-Dalgarno sequence; and said first selectable marker gene comprises a first mutant Shine-Dalgarno sequence; and wherein said first mutant Anti-Shine-Dalgarno sequence and said first mutant Shine-Dalgarno sequence are a mutually compatible pair; thereby forming a first set of transformed host cells; (b) isolating from the first set of transformed host cells those host cells which express the selectable marker gene product; (c) sequencing the first mutant rRNA gene from each host cell isolated in step (b) to identify regions of interest, wherein the regions of interest comprise sequences of one or more nucleic acids which are conserved in each first mutant rRNA gene sequenced; (d) generating a second plurality of mutant rRNA genes wherein the regions of interest from step (c) are mutated; and each rRNA gene further comprises a second mutant Anti-Shine-Dalgarno sequence; (e) inserting the second plurality of mutant rRNA genes comprising the mutated regions of interest from step (d) into a second plurality of plasmids; wherein said plasmids further comprise a second genetically engineered gene which encodes a second selectable marker having a second mutant Shine-Dalgarno sequence, wherein the second mutant Anti-Shine-Dalgarno and the second mutant Shine-Dalgarno sequence are a mutually compatible pair; (f) transforming a second set of host cells with the plasmids from step (e), thereby forming a second set of transformed host cells; (g) isolating from the second set of transformed host cells from step (f) those host cells which express the selectable marker gene product; (h) sequencing the rRNA gene from each host cell isolated in step (g) to identify the mutated regions of interest; (i) screening drug candidates against the mutated regions of interest from step (h) and the wildtype rRNA; (j) identifying the drug candidates from step (i) that bind to the mutated regions of interest from step (h) and the wildtype rRNA; (k) screening the drug candidates from step (j) against a human rRNA; and (l) identifying the drug candidates from step (k) that do not bind to the human rRNA, thereby identifying drug candidates.