The rcsA dependence of the tolB-promoted activation of ugd ( Fig. 2B ) places this RcsB-regulated gene in the first group .
Mutation of the cognate response regulator gene rcsB restored full virulence to the rcsC constitutive mutant , indicating that virulence attenuation results from aberrant expression of RcsB-regulated genes.The virulence attenuation phenotype was partially dependent on the regulatory gene rcsA , which is necessary for transcription of certain RcsB-regulated genes , and on the RcsB-and RcsA-dependent colanic acid capsule synthesis cps operon .
Mutation of the cognate response regulator gene rcsB restored full virulence to the rcsC constitutive mutant , indicating that virulence attenuation results from aberrant expression of RcsB-regulated genes.The virulence attenuation phenotype was partially dependent on the regulatory gene rcsA , which is necessary for transcription of certain RcsB-regulated genes , and on the RcsB-and RcsA-dependent colanic acid capsule synthesis cps operon .
These results indicate that constitutive expression and/or inhibition of RcsB-regulated genes inhibits phagocytosis , possibly resulting from capsule overproduction , and reduces bacterial replication within macrophages in a mechanism that requires genes in addition to rcsA and cps .
The regulatory gene rcsA are responsible , in part , for the virulence attenuation of the rcsC11 mutant Genes under the control of the RcsB protein can be divided into two groups .