TABLE 1.

Complementation of E. coli mutY defect with cloned hMYH^a

Expression plasmid	IPTG	Avg no. of Lac+ revertants/108 cells
pQE30	−	98.3 ± 12.8
pQE30	+	127.9 ± 22.7
pQE30/hMYH	−	8.9 ± 8.8
pQE30/hMYH	+	1.2 ± 1.1

^aFour or five single colonies of the CC104 mutY mutant carrying pREP and expression plasmids were inoculated into Luria-Bertani medium with 100 μg of ampicillin and 25 μg of kanamycin per ml, with or without 1 μM IPTG, and grown overnight at 37°C. Samples were plated on lactose minimal medium and titers were determined on glucose minimal medium. The number of Lac⁺ revertants (mean ± standard deviation) of strain CC104 resulting from G · C-to-T · A transversion is shown.