Team:TMU-Tokyo/Project device1

In frmRAB operon, which origin is chromosome of Escherichia coli, frmAB is normally repressed by frmR. But, when formaldehyde exists, frmR loses its inhibitory and frmAB is expressed.
This device is composed of frmR gene, its promoter and GFP gene.

By using this device, we can visualize formaldehyde with GFP. This visualization system enable to make us know how much of the formaldehyde concentration there is.

■The detail of frmR effect
Christopher D. Herring and Frederick R. Blattner. 2004. Global Transcriptional Effects of a Suppressor tRNA and the Inactivation of the Regulator frmR [PubMed]

fig1. a) When formaldehyde doesn't exist, frmR represses upstream promoter. In this state, transcription is stopped and GFP isn't produced. b) When formaldehyde exists, it makes frmR lose activity. Then promoter is released from frmR's repress and begins to produce GFP.