Abstract
Escherichia coli MelR protein is a transcription activator that is essential for melibiose-dependent expression of the melAB genes. We have used chromatin immunoprecipitation to study the binding of MelR and RNA polymerase to the melAB promoter in vivo. Our results show that MelR is associated with promoter DNA, both in the absence and presence of the inducer melibiose. In contrast, RNA polymerase is recruited to the melAB promoter only in the presence of inducer. The MelR DK261 positive control mutant binds to the melAB promoter but cannot recruit RNA polymerase. Further analysis of immunoprecipitated DNA, by using an Affymetrix GeneChip array, showed that the melAB promoter is the major, if not the sole, target in E. coli for MelR. This was confirmed by a transcriptomics experiment to analyze RNA in cells either with or without melR.
MeSH Terms
Chromatin
DNA-Binding Proteins/genetics,metabolism
DNA-Directed RNA Polymerases/genetics,metabolism
Escherichia coli/genetics,metabolism
Escherichia coli Proteins/genetics,metabolism
Gene Expression Profiling
Gene Expression Regulation, Bacterial
Genome, Bacterial
Melibiose/metabolism
Oligonucleotide Array Sequence Analysis/methods
Precipitin Tests/methods
Promoter Regions, Genetic
Protein Binding
Symporters/genetics,metabolism
Trans-Activators/genetics,metabolism
Chemicals
Chromatin
DNA-Binding Proteins
Escherichia coli Proteins
MelR protein, E coli
Symporters
Trans-Activators
melibiose permease
Melibiose
DNA-Directed RNA Polymerases
Authors & Affiliations
10 authors, click to expand affiliations / ORCID
Grainger David C
School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom. d.grainger@bham.ac.uk.
Overton Timothy W
Reppas Nikos
Wade Joseph T
Tamai Eiji
Hobman Jon L
Constantinidou Chrystala
Struhl Kevin
Church George
Busby Stephen J W
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