Table 1.E. coli strains and plasmids used in this study.

E. coli strain	Relevant details	Reference
EB304	MG1655 Δcas3::apra	This work: detailed in Materials and Methods
IIB796	MG1655 ΔrnhA733::kan	This work: P1 into MG1655 from original E. coli stock center ΔrnhA strain
RCe442	MG1655 ΔproB:: ParaBAD rnhA+-frt > kan > frt	39
BW25113	Δ(araBAD)567 Δ(rhaBAD)568 rph-1 λ- ΔlacZ4748(::rrnB-3)hsdR514 Bacte	For recombineering.38
IIB947	BW25ΔΔ3 lacUV5-cas3 cat:: araBp8-casA	This work: P1 into BW25113 from BW4011440 for recombineering
N4256	MG1655 ΔrecG::kan	41
IIB955	MG1655 pcnBΔ1::kan	This work: derived from strain JVS-2058,42 by P1 into MG1655
IIB967	MG1655 araB::T7 RNAP-tetA	This work: P1 into MG1655 from BL21-AI
IIB968	MG1655 ΔrecG::kan araB::T7 RNAP-tetA	This work: P1 into IIB967 from N4256

Plasmids
pUC19	Empty plasmid vector	43
pEB526/pCas3	cas3 in pUC19	This work
pJLH11/pCas3K320L	cas3K320L in pUC19	This work
pJLH12/pCas3K78L-K320L	cas3K78L-K320L in pUC19	This work
pJLH18/pCas3K78L	cas3K78L in pUC19	This work
pIIB14/pCascade	cse1-cas6e in pUC19	This work
pIIB24/pCasC	casC in pUC19	This work
pEB547	cas3 in pRSF-1b	16
pEB574	cas3 in pACYCDuet-1	This work