Mutations in the nucleotide binding and hydrolysis domains of Helicobacter pylori MutS2 lead to altered biochemical activities and inactivation of its in vivo function

Table 3 DNA cleavage rates (pM min⁻¹) determined for HpMutS2 and mutants

	No nucleotide	+ ATP	+ ADP	+ ATPγS
Single-stranded DNA
HpMutS2	24.82 ± 1.15	32.08 ± 5.32	28.11 ± 5.15	28.5 ± 3.68
HpMutS2-G338R	40.19 ± 8.73	40.45 ± 9.52	38.87 ± 8.79	ND
HpMutS2-E413A	6.50 ± 0.55	7.23 ± 0.65	6.90 ± 1.4	ND
HpMutS2ΔSmr-D30A	2.12 ± 1.67	ND	ND	ND
Holliday junction
HpMutS2	26.49 ± 3.95	37.77 ± 8.59	18.85 ± 1.9	17.44 ± 0.84
HpMutS2-G338R	41.59 ± 9.53	43.7 ± 11.42	41.6 ± 10.27	ND
HpMutS2-E413A	4.92 ± 1.25	1.27 ± 1.01	6.77 ± 3.53	ND
HpMutS2ΔSmr-D30A	3.34 ± 1.67	ND	ND	ND

Reaction rates were estimated by dividing the total product formed by corresponding incubation time obtained from the linear range of enzymatic activity (Figs. 6a-f). The error values represent standard deviation from two or more different time points. ND, not determined