Insights into the role of Val45 and Gln182 of Escherichia coli MutY in DNA substrate binding and specificity

BMC Biochemistry

Table 3 Mutation frequencies of λDE3-containing E. coli mutM mutY mutant strains.

Strain	Mutation Frequency (Rif^R/10⁸ cells)	Fold	Mutation frequency (Lac⁺/10⁸ cells)	Fold
1. CC104 (WT)	4.1 ± 1.3	1	1.2 ± 1.0	1
2. CC104 mutMmutY	1464 ± 314	357	486 ± 65	408
3. CC104M^-Y^- + pET11a^a	2055 ± 704	501	156 ± 102	130
4. CC104M^-Y^- + pET-MutY^b	8.8 ± 4.4	2	0.9 ± 0.8	0.8
5. CC104M^-Y^- + pET-V45A^c	630 ± 177	154	6.3 ± 2.1	5.3
6. CC104M^-Y^- + pET-Q182L^d	181 ± 74	44	10.2 ± 8.7	8.5
7. CC104M^-Y^- + pET-V45A/Q182L^e	728 ± 358	178	20 ± 13	16.7

^a The strain CC104 mutM mutY contains pET11a which is the expression vector for wild-type and mutant MutY expression. ^b-e The strain CC104 mutM mutY expresses indicated MutY protein cloned in the pET11a vector.

ISSN: 1471-2091