TABLE 3.

Mutation frequencies in strain CC105 harboring pBR329 plasmids with cloned mutated mutD genes^a

Strain	Mutation frequency (108)
	Rifr	Lac+
Wild type	3.8	0.9
H24G	2.5	0.4
H28G	7.2	5.2
H49G	4.4	2.7
H66G	49.0	27.7
H98G	1,282.2	142.4
H162G	3,680.4	66.6
H225G	4.0	0.5

^aEach mutant carries an altered mutD gene, which results in a histidine-to-glycine change at the indicated amino acid position in the ɛ subunit. For details, see the footnote to Table 1.