Difference between revisions of "Part:BBa K613015"

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TetR E37A W43S T141A mutant

This is a TetR mutant, who carries the triple mutation EA37WS43TA141. Is part of the muTetR toolkit.

In vitro characterization

Using the MITOMI technique we determined the DNA binding landscape of the TetR E37A T41A W43S mutant. To do so, first we designed and generated the library of double stranded DNA sequences that cover all possible single base substitution within the tetO operator sequence. Based on that library we measured the dissociation constants of the mutant to variable tetO-like sequences and determined the specificity of the mutant to the tet operator sequence (expressed as a PWM).

WebLogo we obtained for the E37A T41A W43S mutant:

Workman CT, Yin Y, Corcoran DL, Ideker T, Stormo GD, Benos PV. enoLOGOS: a versatile web tool for energy normalized sequence logos. Nucleic Acids Res. 2005 Jul 1;33:W389-92.

In vivo characterization

This TetR mutant was characterized in vivo by putting it into pSB3K1 under a constitutive promoter (J23116). This plasmid was cotransformed with J61002 harbouring RFP under pTet promoter (B0040) in DH5alpha cells. Cells were grown in a medium containing Kanamycin & Amplicillin plus different concentrations of ATC, ranging from 0 to 2000 ng/mL. OD600 absorbence and RFP fluorescence were measured every 10 minutes during 12 hours on a platereader machine.

Induction curves

Fluorescence measurements (RFUs) were normalized by OD600 values.

Dose-response curve

Fluorescence measurements (RFUs) were normalized by OD600 values. For each ATC concentration, we estimated the steady-state fluorescence expression by averaging the measurements over the last hour.

Sequence and Features