Regulation of bacterial respiration: Comparison of microarray and comparative genomics data

A comparison was made of the structures of the Fnr and ArcA modulons and regulons. The data on modulon composition were taken from published microarray assays, whereas regulons were characterized using comparative genomic approaches. The regulatory cascade involving Fnr and ArcA contributes greatly to the extension of the Fnr modulon over the Fnr regulon by adding operons of the ArcA modulon. The Fnr and ArcA regulons were shown to contain 26 and 16 operons, respectively. Ten operons had high-score and highly conserved sites for both Fnr and ArcA and were isolated as a so-called core of regulons.