Recognition of nucleotide sequences at the Escherichia coli galactose operon P1 promoter by RNA polymerase.
Specific nucleotide (nt) sequences in the -35 region are not essential for galP1 promoter activity, whereas nt sequences in the spacer region are needed for transcription initiation: a G:C base pair at nt -14 and sequences upstream from this position are necessary. In the absence of these sequences, transcription initiation is dependent on the insertion of oligodeoxyribonucleotides carrying -35 region consensus hexamer sequences. Additionally, for maximal promoter activity, specific sequences just upstream from nt -49 are required. Because galP1 carries no sequence resembling the -35 region consensus hexamer, we propose that recognition by RNA polymerase proceeds via an unusual mechanism involving contacts upstream from the -10 hexamer, distortion of the spacer region and a contact upstream from nt -49.
Chan
B
B
School of Biochemistry, University of Birmingham, U.K.
Busby
S
S
D001483:Base Sequence; D002872:Chromosome Deletion; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics* / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D003851:Deoxyribonucleases; D004926:Escherichia coli / Q000235:genetics*; D005690:Galactose / Q000235:genetics*; D008969:Molecular Sequence Data; D009876:Operon; D011401:Promoter Regions, Genetic; D014158:Transcription, Genetic
D004269:DNA, Bacterial; D012321:DNA-Directed RNA Polymerases; D003851:Deoxyribonucleases; D005690:Galactose