• Transcription;
  • Promoter;
  • cepA;
  • Bacteroides fragilis


There is little known about the sequences that mediate the initiation of transcription in Bacteroides fragilis, thus transcriptional start sites for 13 new genes were determined and a total of 23 promoter regions upstream of the start sites were aligned and similarities were noted. A region at about −7 contained a consensus sequence of TAnnTTTG and upstream in the region centered at about −33, another TTTG motif was found in the majority of promoters examined. Canonical, Escherichia coli, −10 and −35 consensus sequences were not readily apparent. Mutations within the −7 motif indicated the TTTG residues were essential since changes in this sequence reduced the promoter activity to that of a no promoter control in a chloramphenicol acetyl transferase transcriptional fusion model system. Additional fusion studies indicated that the −33 region was also necessary for full activity.