TABLE 2.

Number of replicated vector molecules with a normal or mutant sequence at the T-T dimer site, ratio of 3′ T→A to 3′ T→C mutations, and bypass error rate in uvrA6 strains expressing (where indicated) UmuDC or MucAB proteins or their mutagenically active counterparts UmuD′C or Muc A′B from low-copy-number plasmids

Strain	Relevant genotype	Plasmid	UV light fluence (J/m2)	Sequence at T-T dimer site (no.)				A/C ratioa	Error rate (%)
				T-T	T-A	T-C	Other
TK603	umuDC+	None	0	204	0	1	0		0.5
			4	540	27	3	1	9.0	5.4
DV12	umuDC+mutD5	None	0	183	2	4	0	0.5	3.2
			4	355	18	1	1	18.0	5.3
RW82	ΔumuDC	UmuDC	0	627	26	10	2	2.6	5.7
			4	1,860	95	21	5	4.5	6.1
		UmuD′C	0	1,011	40	15	1	2.7	5.3
			4	1,041	72	7	3	10.3	7.3
		MucAB	0	1,758	9	46	3	0.20	3.2
			4	2,040	9	39	1	0.23	2.4
		MucA′B	0	1,214	1	40	6	0.03	3.7
			4	1,202	5	38	3	0.13	3.7
DV02	ΔumuDC ΔdnaQ spq-2	UmuDC	0	535	14	23	3	0.61	7.0
			4	740	43	7	4	6.1	6.8
		UmuD′C	0	874	34	24	2	1.4	6.4
			4	894	39	11	1	3.5	5.4
		MucAB	0	722	1	18	1	0.06	2.7
			4	730	2	11	1	0.18	1.9
		MucA′B	0	1,016	7	59	4	0.12	6.5
			4	1,032	8	39	5	0.21	4.8
DV03	ΔumuDC dnaQ+spq-2	UmuDC	0	62	3	1	0	3.0	6.1
			4	317	26	5	1	5.2	9.2
		MucAB	0	763	4	25	6	0.16	4.4
			4	389	1	10	1	0.10	3.0
DV05	ΔumuDC mutD5	UmuDC	0	89	1	4	0	0.25	5.3
			4	387	19	5	0	3.8	5.8
		MucAB	0	380	1	8	0	0.13	2.3
			4	624	0	12	1		2.0
DV01	ΔumuDC ΔholE	UmuDC	0	122	5	2	0	2.5	5.4
			4	120	7	5	0	1.4	9.1
		UmuD′C	0	141	8	1	0	8.0	6.0
			4	172	10	0	0	10.0	5.5
		MucAB	0	274	0	3	0		1.1
			4	377	0	9	0		2.3
		MucA′B	0	59	0	0	0		0.0
			4	115	0	5	0		4.2

^aRatio of 3′ T→A to 3′ T→C mutations.