Summary of the findings
Construct name | Structure | Nuclease | Recombinasea | Viabilityb |
---|---|---|---|---|
vector | NA | NA | NA | - |
pRecBCD | + | + | + | + |
pAddAB | - | + | + | + |
pRecBC | ± | ± | + | + |
pRecBCc | ± | -c | ? | -c |
pRecB1080 | + | - | - | - |
pRecB*CD | + | + | - | + |
pAddAB- | - | - | - | - |
pRecD | - | - | - | - |
The three properties of the RecBCD enzyme, relevant for the RecA-independent role in cell viability, are “structure,” DNA degradation (“nuclease”), and recombinational repair (“recombinase”). “+,” wild-type levels; “±,” partial levels; “-,” lack of property; “?,” “unknown”; NA, not applicable.
↵a In ΔrecBCD mutant cells.
↵b In ΔrecA ΔrecBCD mutant cells.
↵c In ssDNA-exonuclease-deficient ΔrecA ΔrecBCD mutant cells.