Effects of the Escherichia coli sfsA Gene on mal Genes Expression and a DNA Binding Activity of SfsA

Abstract

The sfsA gene was identified as one of the sfs genes the over-expression of which stimulates maltose fermentation of the Mal^- Escherichia coli strain MK2001 (crp^*1, cya:Km^r). Expression from the malPQ promoter, which was measured using a chromosomally integrated malPp-lacZ fusion, was induced by over-expressing the sfsA gene in the crp^*1, cya: Km^r strain. The level of the MalE protein was increased in crp^*1, cya:Km^r cells over-producing SfsA. The SfsA protein was purified to homogeneity and tested for DNA binding activity. The purified SfsA protein binds to DNA non-specifically. All these results may suggest that SfsA functions as a DNA binding protein to induce the mal genes in coordination with CRP^*1.