Figure 2
From: The mechanism of a formaldehyde-sensing transcriptional regulator
EcFrmR-mediated repression of frmRAB expression is relieved by formaldehyde.
(a) Cultures of E. coli PC677 carrying Pfrm-frmR-lacZ (open bars) or Pfrm-frmRstop-lacZ (gray bars) were grown as described in Methods in the absence and presence of the indicated concentrations of formaldehyde. β-Galactosidase activities (Miller units plotted on a log scale) were measured as a proxy for in vivo transcription from the frmRAB promoter. (b) β-Galactosidase activities (Miller units) of cultures of E. coli PC677 carrying Pfrm-frmR-lacZ were measured after anaerobic cultivation in the presence of the indicated aldehydes as described in Methods. Activities were normalized to that measured in the absence of formaldehyde. For both panels, the error bars represent the standard deviation from the mean (n = 3).
