FIG. 7.

The structural properties of the N-terminally truncated σ^A. (A) Partial proteolysis analyses of the N-terminally truncated σ^A. The truncated σ^A subunits were partially digested with trypsin (top panel) or chymotrypsin (bottom panel) (see Materials and Methods). The time points (in minutes) to stop the proteolytic reaction are shown on top of each panel. (B) CD spectra of the N-terminally truncated σ^A. Each of the N-terminally truncated σ^A (0.2 mg/ml) subunits was scanned with UV light from 190 to 260 nm. The absorption curves for the truncated σ^A are as indicated.