TABLE 1.

Plasmids used in this study

Plasmid	Description	Source or reference
pPOT1	pGEX-derived plasmid used to clone the library of rRNA gene fragments	44; transcription of the RNA fragment (from Ptac) is IPTG inducible
pA750	pPOT1, from the library, containing the 32-nucleotide rDNA fragment whose transcript is complementary to nucleotides 735 to 766 of 23S rRNA	This work
pS750	pPOT1 with the A750 insert in the opposite transcriptional orientation, yielding a transcript corresponding to the direct sequence of nucleotides 735 to 766 of 23S rRNA	This work
pACYC184	Contains the wild-type cat gene	14
pCAT101	pACYC184 derivative containing the cat gene with a UGA nonsense mutation at codon 74	This work
pCAT102	pACYC184 derivative containing the cat gene with a UAA nonsense mutation at codon 74	This work
pCAT103	pACYC184 derivative containing the cat gene with a UAG nonsense mutation at codon 74	This work
pNC160	Randomly chosen plasmid from the rRNA fragment library which contains a 160-nucleotide rRNA gene fragment whose transcript is complementary to nucleotides 377 to 537 of 23S rRNA	This work