FIG. 4.

Levels of δRz-E196 expression in different conditions. Levels of ribozyme expression were assessed by Northern blot hybridization with total RNA from L. lactis (IL1403/pMSP3535) grown at different temperatures (30°C and 37°C) (A) and with different nisin concentrations (B). (C) Stability of δRz in strain IL1403/pMSP3535. Ribozyme expression was triggered by addition of nisin for 1 h. Then transcription was stopped using rifampin, and aliquots were removed at different times and subsequently analyzed by Northern blot hybridization. (D) Graphic representation of the stability (panel C) of δRz and its precursor (Pre-δRz) as a function of time.