FIG 2.

Mutations identified in unusually large colonies of E. coli ΔargC proA* cells after growth in M9/glucose for 6 days followed by plating on M9/glucose. (A) Locations of point mutations in the proBA* operon. (B) Sequences surrounding point mutations M1 and M2 in the promoter of the proBA operon. The E. coli consensus sequence was defined in references 51 and 52. The ex-10 TG element is underlined. The dashed line indicates the transcription start site identified by Thomason et al. (24), and the black lines indicate the transcription start sites identified by Cho et al. (53). WT, wild type. (C) Region in the 3′ end of proB that encodes a weak promoter for proA. The red line indicates the transcription start site identified by 5′-RACE and the dashed line indicates the transcription start site identified by Thomason et al. (24).