Fig. 2.

The role of CcpA in promoters cid and lrg. a–b; The promoter regions of cid (a) and lrg (b). The 5′ termini of the cid and lrg coding region transcripts were mapped using 5′ RACE. The potential transcriptional start sites (TSSs) are numerically denoted (+1) in bold, and −10/–35 sequences are indicated by upper case letters. The hypothetical cre sites underlined. c–d; Electrophoretic mobility shift assays (EMSAs) of CcpA binding with the promoter region of the lrg (c) or cid (d) gene. Biotin-labelled promoter regions (4 fmol) of lrg (a) and cid (b) were incubated with increasing amounts of purified His-CcpA protein (0, 1.5625, 3.125, 6.25, 12.5, 25 and 50 pmol). Unlabelled promoter regions (0.1 and 1 pmol) were added to the binding reaction mixtures (lanes 8 and 9). The reactions were run on a non-denaturing polyacrylamide gel and the signal observed via chemiluminescence.