Team:Davidson-Missouri Western/Improvement of pre-existing Registry parts

From 2008.igem.org

Improved function by a modified Lac promoter - Mutations were introduced into the wild type Lac promoter that exists in the Registry. One mutant promoter, designated pLacIQ1, had improved ability to promote, as demonstrated by the following experiment.


Constructs were assembled with eiter the wild type Lac promoter or mutant promoters driving GFP expression via part number E0240. Fluorescence measurements taken at 16 or 24 hours were corrected for optical density.

16 hours

Sample Fluorescence Optical Density Fluor/OD
LB 2 0.043 46.5
E0240 0.67 1.262 0.53
S04020 4.67 1.225 3.81
S04021 21 1.201 17.49
K091131 68 1.188 57.24

24 hours

Sample Fluorescence Optical Density Fluor/OD
LB 1 0.047 21.3
E0240 3.0 1.201 2.50
S04020 4.0 1.239 3.23
S04021 14.5 1.216 11.92
K091131 71.3 1.207 59.07

16 hr.JPG

24 hr.JPG

Mutations were also introduced into the LacI repressor gene in order to improve its ability to bind to the operator site in the Lac promoter.

Part Description plasmid size
BBa_K091121LacI wild-type gene 1083
BBa_K091122LacI_I12 1083
BBa_K091127LacI_I12_X86 1083