Nucleic Acids Research, 1984, Vol. 12, No. 13 5449-5464
© 1984
MOLECULAR BIOLOGY |
Deletion analysis of the CAP-cAMP binding site of the Escherichia coil lactose promoter
Department of Biochemistry, College of Agricultural and Life Sciences, University of Wisconsin Madison, WI 53706, USA
Received April 9, 1984. Revised June 8, 1984. Accepted June 8, 1984.
S1 nuclease was used to generate a series of deletions which extend into tAe CAP-cANP binding site from upstream of the Escherichia coli lactose operon promoter (lacP). Deletion and insertion mutations were also created which changed the spacing region between the CAP-cAMP binding site and the lacP -35 region. The promoter activities of these mutations were compared by measuring the levels of ß-galactosidase gene expression in vivo. The results show that sequence information prior to 74 base pairs (–74) upstream from the transcription start site (designated as +1) is not necessary for the full activation of the lac promoter by the CAP-cAMP complex. However, the deletion which extends to the –71 position retains only one third of the promoter activity in the presence of the CAP-cAMP complex. Removal of one symmetrical element from the two fold symmetry in the CAP-cAMP binding site abolished the CAP-cAMP stimulation of the lac promoter. Spacer muta tions which increase by one base pair or decrease by two base pairs the length of the spacing region between the CAP-cAMP binding site and the lacP-35 region drastically reduced the CAP-cAMP stimulation of the lac promoter. This suggests that the distance between the lac promoter transcription start site and CAP-cAMP binding site is crucial for the function of the lac promoter, despite the fact that this distance varies in other E. coli promoters positively regulated by CAP-cAMP. A deletion which extends to the –59 position results in a two fold enhanced expression of lac in the absence of CAP-cAMP. This is consistent with the existance of a competitive RNA polymerase binding site in this region which would normally act to inhibit RNA polymerase binding.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  J. Song, T. Xia, and R. A. Jensen PhhB, a Pseudomonas aeruginosa Homolog of Mammalian Pterin 4a-Carbinolamine Dehydratase/DCoH, Does Not Regulate Expression of Phenylalanine Hydroxylase at the Transcriptional Level J. Bacteriol., May 1, 1999; 181(9): 2789 - 2796. [Abstract] [Full Text]
|
|
|
|
|
|
I. R. Henderson and P. Owen The Major Phase-Variable Outer Membrane Protein of Escherichia coli Structurally Resembles the Immunoglobulin A1 Protease Class of Exported Protein and Is Regulated by a Novel Mechanism Involving Dam and OxyR J. Bacteriol., April 1, 1999; 181(7): 2132 - 2141. [Abstract] [Full Text]
|
|
|
|
|
|
Q. Bai and R. L. Somerville Integration Host Factor and Cyclic AMP Receptor Protein Are Required for TyrR-Mediated Activation of tpl in Citrobacter freundii J. Bacteriol., December 1, 1998; 180(23): 6173 - 6186. [Abstract] [Full Text]
|
|
|
|
 |
|
 F W Whipple, N H Kuldell, L A Cheatham, and A Hochschild Specificity determinants for the interaction of lambda repressor and P22 repressor dimers. Genes & Dev., May 15, 1994; 8(10): 1212 - 1223. [Abstract] [PDF]
|
|