The function of CsgD in rdar morphotype expression The csgD gene encodes for a transcriptional regulator of the LuxR superfamily .
In order to determine which CsgD-regulated factor , either curli fimbriae or cellulose , was responsible for restoring the biofilm phenotype in 3934 ∆ stm2689 [ pBR328 : : csgD ] , 3934 ∆ stm2689 strain was complemented with the adrA gene under the control of its own promoter , which exclusively activates cellulose A C Arabinose 0.1 % Glucose 0.1 % 3934 3934BADstm2689 B 3934BADstm2689 3934 3934 ara gluc ∆ stm2689 205 kD Fig. 3 .
To investigate on which level the regulation of CsgD expression occurs , the transcription of csgD was measured by real-time RT-PCR analysis .
Group III is represented by OmrA/B , which by binding directly to flhDC and csgD mRNA [ 62,75 ] , can down-regulate both motility and the expression of CsgD-controlled curli fibres and cellulose .
Alternatively , the leaf persistence competition defect of the STM4264 mutant may be unrelated to the regulation of CsgD since the csgD mutant had no defect in the phyllosphere .
The colony morphology of the csgD strain closely matched that of Fig. 6A that are regulated by CsgD .
The colony morphology of the csgD strain closely matched that of the WT strain that are regulated by CsgD .
To quantitate the degree of CsgD complementation in each strain , we measured the expression of csgD , coding for curli fimbria production , coding for a regulator of cellulose production , using promoter-lux operon fusion plasmids .