Fig. 1

Effect of dCas9 binding position and orientation. a Distribution of the fitness effect of guide RNAs in our library depending on target gene essentiality and target strand. b Rolling average of the fitness effect produced by guides targeting the promoter of essential genes in both orientations (rolling window size of 50 bp). c Examples of polar effect seen in the cydDC and ycaR-kdsB operons. Gene cydC and kdsB highlighted in red are essential but not gene cydD and ycaR. Guides binding to the coding strand are shown as blue dots. d Example of operons containing an essential gene followed by a non-essential gene. Targeting the downstream non-essential gene usually does not produce a fitness defect. e Rolling average of the fitness effect produced by guides targeting the end of essential genes (rolling window size of 50 bp). f Rolling average of the fitness effect produced by guides along the length of essential genes. Gene start is 0 and gene end is 1 (rolling window size is 5% of the gene length). In all rolling average plots, the shaded area represents the standard deviation