Proteome analysis of factor for inversion stimulation (Fis) overproduction in Escherichia coli

The factor-for-inversion stimulation protein (Fis) is a global regulatory protein in Escherichia coli that activates ribosomal RNA (rRNA) transcription by binding to three upstream activation sites of the rRNA promoter and enhances transcription 5- to 10-fold in vivo. Fis overexpression results in different effects on cell growth depending on nutrient conditions. Differential proteome analysis of Fis-expressing cells shows ten protein spots corresponding to Fis overexpression in both rich (YT) and minimal (M9+glucose) media. Three of these spots have been identified as elongation factor TS, histidine-binding periplasmic protein precursor, and ketol-acid reductoisomerase.