FIG 2.
Deletion analysis of the ilv-leu promoter region to determine a region necessary for CA of ilv-leu upstream of the cre site (UC region). (A) Cells of strains FU714 (−165), FU715 (−150), FU1179 (−140), FU1178 (−130), FU1177 (−120), FU1176 (−110), FU716 (−100), and FU717 (−55) carrying a lacZ fusion of various promoter regions (nt −165, −150, −140, −130, −120, −110, −100, and −55 to +26) in amyE, respectively, were grown to an OD600 of 0.5 under nitrogen-limited conditions, and then β-Gal activity in crude cell extracts was measured. The average β-Gal activities (with standard deviations), which were obtained from at least two independent lacZ monitoring experiments, are shown. The promoter region (nt −55/+26) does not contain the cre site, whereas the others contain cre and various lengths of a region upstream of cre. The region upstream of cre necessary for full CA of ilv-leu (UC region) is indicated. (B) Cells of strains FU676 (nt −248/+26, −248), FU715 (−150), FU716 (−100), and FU717 (−55) were grown under AA-rich growth conditions, and then β-Gal activity in crude cell extracts was measured.