An upstream activating sequence containing curved DNA involved in activation of the Clostridium perfringens plc promoter

The in vivo transcriptional activity of the plasmid-borne plc gene, which encodes phospholipase C (alpha-toxin) of Clostridium perfringens, was stimulated by a curved-DNA-containing sequence, depending on its proper linear and rotational orientation. The transcriptional activity was also stimulated by the upstream sequence. Moreover, the stimulatory effect of the sequence and the degree of DNA bending were greater at lower temperature. A similar temperature effect was also seen with the chromosomal plc gene.