TABLE 2.

Effect of RecG on UV sensitivity of exonuclease-depleted strains

xonA, xseA, sbcCD, exoX, recJ genotype	Exonuclease deficiency (polarity)	rec+ constructs		ΔrecG constructs
		Strain	Survivala	Strain	Survivala
Wild type	None	TB28	0.68	N5742	0.14
xonA	ExoI− (3′–5′)	N6946	0.67	N7293	0.21
xseA	ExoVII− (3′–5′ and 5′–3′)	N6951	0.68	N7297	0.11
sbcCD	SbcCD− (3′–5′)	N5281	0.59	N7295	0.11
recJ	RecJ− (5′–3′)	N4934	0.62	N7294	0.044
xonA xseA	ExoI− ExoVII−	N6954	0.58	N7301	0.093
xonA sbcCD	ExoI− SbcCD−	N6945	0.44	N7299	0.059
xonA recJ	ExoI− RecJ−	N7065	0.22	N7298	0.028
xseA sbcCD	ExoVII− SbcCD−	N6952	0.65	N7303	0.13
xseA recJ	ExoVII− RecJ−	N7066	0.32	N7302	0.0028
sbcCD exoX	SbcCD− ExoX−	N7004	0.80	NCb
sbcCD recJ	SbcCD− RecJ−	N7056	0.63	N7300	0.0067
xonA xseA sbcCD	ExoI− ExoVII− SbcCD−	N6953	0.33	Inviablec
		N7037	0.30
xonA xseA recJ	ExoI− ExoVII− RecJ−	N7036	0.0072	N7317d	0.001d
xonA sbcCD exoX	ExoI− SbcCD− ExoX−	N7005	0.49	NCb
xonA sbcCD recJ	ExoI− SbcCD− RecJ−	N7063	0.17	N7312	0.011
xseA sbcCD exoX	ExoVII− SbcCD− ExoX−	N7006	0.79	NCb
xseA sbcCD recJ	ExoVII− SbcCD− RecJ−	N7064	0.21	N7311	0.00025
xonA xseA sbcCD exoX	ExoI− ExoVII− SbcCD− ExoX−	N7007	0.23	NCb
xonA xseA sbcCD recJ	ExoI− ExoVII− SbcCD− RecJ−	N7074d	0.001d	inviablec

^aSurvival was determined at a dose of 30 J/m². Except where indicated otherwise, survival was determined by using cultures grown to exponential phase in LB broth and irradiated on the surface of LB agar plates. Values are means of three to seven experiments.

^bNC, not constructed.

^cAs revealed by using synthetic lethality constructs carrying pJJ100 (recG⁺).

^dThese strains cannot be subcultured on LB agar (N7074) or subculture poorly (N7317), but can be grown with no difficulty, and their UV survival determined, by using 56/2 glucose minimal salts media under otherwise identical conditions.