FIG. 1.

Deletion analysis of the sed promoter. Arrows indicate the inverted repeat sequence located within the intergenic region of sed and sej. The transcription start site of sed is indicated as +1. Lines represent the remaining part of the sed promoter which were fused with a promoterless cat gene in pMH109. Deletions are numbered according to distance from the transcription start site. Promoter activities were analyzed by measuring CAT expression levels in both KSI2054 (Agr⁺) and ISP546 (Agr⁻) host strains (33). CAT values were converted to relative expression (Rel. Exp.), which is the value obtained with the deletion mutant divided by the value obtained with the wild-type sed promoter in strain KSI2054. The agr stimulation index (ASI) is the CAT value obtained with KSI2054 divided by the value obtained from ISP546 cells bearing the same plasmid.