Fig. 5:

Analysis of TATA box mutants at the transcriptional (A) and translational (B) levels. (A) Primer extension analysis of bop mRNA in 4 bop promoter TATA-box mutants using crude RNA is shown with strain designations labeled above. The controls used in this experiment were the Pum- (bop-) host strain SD23, strain 100E (SD23 containing plasmid with unmutated promoter) and TATA box mutants (1B2, 2B12, 2H10 and 1D2). A sequencing reaction (C lane) performed with the same primer on pMS1 template (plasmid containing the cloned bop gene) is shown as is the double stranded sequence across the transcription start point (start site and direction indicated by arrow). (B) Spectra (absorbance versus wavelength from 400 to 700 nm) of purple membrane preparations for the 4 TATA-box mutant strains and the 2 controls strains (same as in part A) are shown. Relative BR content was quantified from comparison of absorbance at 568 nm to that at 280 nm.