Genomics of the marA/soxS/rob regulon of Escherichia coli: identification of directly activated promoters by application of molecular genetics and informatics to microarray data.

摘要: Summary Microarray analyses are providing a plethora of data concerning transcriptional responses to specific gene regulators and their inducers but do not distinguish between direct indirect responses. Here, we identify directly activated promoters the overlapping marA, soxS rob regulon(s) Escherichia coli by applying informatics, genomics molecular genetics microarray obtained others. Those studies found that overexpression or treatment cells with salicylate derepress paraquat induce soxS, resulted in elevated transcription 153 genes. However, only 27 out showed increased under at least two aforementioned conditions eight those were previously known be activated. A computer algorithm was used potential activator binding sites located upstream remaining 19 this subset, conventional genetic biochemical approaches applied test whether these critical for activation homologous MarA, SoxS Rob activators. Only seven when fused lacZ tested as single lysogens. All contained an essential site. The insensitive stimulation suggesting great majority transcripts either misidentified from effects requiring sequences outside promoter region. We estimate total number regulon is less than 40.