FIG. 3.

A comparative assessment of CAT activities supported by various modified pS16.2 constructs with and without the TGN motif in mycobacteria and E. coli. The unique SphI restriction site in pS16.2 and pS16.2(TG⁻) was used to generate the various modified promoter derivatives as described in Table 1. The extended −10 sequence (identical for all constructs) and the −35 region (different for each construct) are indicated. The CAT specific activity (Sp. Act.) was determined as described elsewhere (7) and is expressed as nanomoles of chloramphenicol converted into its acetylated derivatives per minute per milligram of protein. M. sm., M. smegmatis.