pT181 is a 4.4 kb Staphylococcus aureus plasmid which confers tetracycline resistance on its host. Recent genetic and biochemical studies suggest that plasmid replication is regulated at the level of RepC synthesis. This regulation apparently involves a small plasmid coded RNA which seems to inhibit the expression of the repC gene. This inhibition could involve initiation of transcription, attenuation of transcription, or initiation of translation. The project will focus on the role of the promoters and the terminator preceding repC in the regulation of RepC synthesis.