The Escherichia coli serS gene promoter region overlaps with the rarA gene

Deletion of the entire gene encoding the RarA protein of Escherichia coli results in a growth defect and additional deficiencies that were initially ascribed to a lack of RarA function. Further work revealed that most of the effects reflected the presence of sequences in the rarA gene that affect expression of the downstream gene, serS. The serS gene encodes the seryl aminoacyl-tRNA synthetase. Decreases in the expression of serS can trigger the stringent response. The sequences that affect serS expression are located in the last 15 nucleotides of the rarA gene.

Automated summary

Deletion of the entire gene encoding the RarA protein in Escherichia coli leads to growth defects and additional deficiencies. However, it was later discovered that most of these effects are actually due to sequences in the rarA gene that affect the expression of the downstream gene, serS.