Figure 6

Patterns of induction and repression ratios for the proximal lacO promoter library characterized using a SGFP2 reporter construct carried on pPMQAK1 [25]. The number in prox-# indicates the distance between the center of the proximal symmetric lac operator and the transcriptional start site of a Ptrc core promoter. The time in hours represents time from start of experiment. J23101 corresponds to BioBrick BBa_J23101 (iGEM Registry [34]) and is a constitutive control promoter without lac operator. A. Time-course study of induction ratios (fluorescence per cell values of 2 mM IPTG induced cultures/the values of the non-induced cultures) in E. coli DH5αZ1. Error bars represent the estimation of the standard error of the mean for the induction ratios (n = 6). B. Induction ratios in the Synechocystis PCC 6803 strain expressing LacI (this work). Error bars represent the estimation of the standard error of the mean for the induction ratios (n = 2). C. Repression ratios (fluorescence per cell values of cultures from the chloramphenicol resistance-only Synechocystis strain (LacI negative, this work)/the values of cultures from the Synechocystis PCC 6803 strain expressing LacI). Error bars represent the estimation of the standard error of the mean for the repression ratios (n = 2). nd, not determined.