Аннотация:Summary We have systematically examined the mRNA profiles of 36 two‐component deletion mutants, which include all two‐component regulatory systems of Escherichia coli , under a single growth condition. DNA microarray results revealed that the mutants belong to one of three groups based on their gene expression profiles in Luria–Bertani broth under aerobic conditions: (i) those with no or little change; (ii) those with significant changes; and (iii) those with drastic changes. Under these conditions, the anaeroresponsive ArcB/ArcA system, the osmoresponsive EnvZ/OmpR system and the response regulator UvrY showed the most drastic changes. Cellular functions such as flagellar synthesis and expression of the RpoS regulon were affected by multiple two‐component systems. A high correlation coefficient of expression profile was found between several two‐component mutants. Together, these results support the view that a network of functional interactions, such as cross‐regulation, exists between different two‐component systems. The compiled data are avail‐able at our website ( http:ecoli.aist‐nara.ac.jpxpanalysis 2components ).