Analysis of cepA and other Bacteroides fragilis genes reveals a unique promoter structure.
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.
Bayley
D P
DP
Department of Microbiology and Immunology, 600 Moye Blvd., East Carolina University School of Medicine, Greenville, NC 27858-4354, USA.
Rocha
E R
ER
Smith
C J
CJ
D019677:Artificial Gene Fusion; D001441:Bacteroides fragilis / Q000235:genetics*; D001483:Base Sequence; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D009154:Mutation; D011401:Promoter Regions, Genetic; D016415:Sequence Alignment; D001618:beta-Lactamases / Q000235:genetics*
D004269:DNA, Bacterial; D015500:Chloramphenicol O-Acetyltransferase; D001618:beta-Lactamases