Mutational analysis of an archaeal minichromosome maintenance protein exterior hairpin reveals critical residues for helicase activity and DNA binding

Table 1 Kinetic parameters of EXT-hp mutants

	ATpase activity		ATpase + Y-DNA		ssDNA Binding		Y-DNA Binding
Mutant	k_cat, min^-1	k_m, nM	k_cat, min^-1	k_m, nM	k_d, nM	Hill	k_d, nM	Hill
WT	3.1 ± 0.1	170 ± 20	3.8 ± 0.1	190 ± 20	240 ± 0.5	8.8 ± 0.5	224 ± 7.3	5.8 ± 1.3
M1	1.8 ± 0.1	140 ± 30	3.7 ± 0.5	440 ± 150	317 ± 5.8	4.4 ± 0.3	398 ± 4.0	13.2 ± 1.3
M2	2.4 ± 0.1	120 ± 20	3.6 ± 0.1	160 ± 20	209 ± 5.8	4.7 ± 0.5	230 ± 7.2	10.1 ± 3.3
M3	4.7 ± 0.3	270 ± 40	5.2 ± 0.2	260 ± 30	169 ± 1.3	5.6 ± 0.1	186 ± 6.4	7.9 ± 1.1
M4	3.9 ± 0.1	230 ± 10	5.3 ± 0.2	260 ± 30	165 ± 10.0	13.4 ± 4.3	178 ± 1.5	7.7 ± 0.5
M5	2.9 ± 0.2	60 ± 40	3.7 ± 0.2	180 ± 30	185 ± 0.3	12.1 ± 0.3	224 ± 0.9	11.6 ± 0.4
M6	2.3 ± 0.1	100 ± 20	2.6 ± 0.2	130 ± 30	283 ± 78.7	15.6 ± 20.1	400 ± 6.5	5.6 ± 0.4
M7	2.0 ± 0.1	90 ± 10	2.2 ± 0.1	90 ± 20	444 ± 1.0	10.6 ± 0.5	404 ± 2.6	8.8 ± 0.4
M8	1.8 ± 0.1	170 ± 40	1.7 ± 0.1	170 ± 30	380 ± 1.8	8.0 ± 0.3	483 ± 0.4	9.0 ± 0.03
M9	No Activity		No Activity		325 ± 8.3	6.2 ± 0.8	428 ± 2.0	12.9 ± 0.5
M10	No Activity		No Activity		267 ± 7.0	4.5 ± 0.5	339 ± 2.6	11.4 ± 2.0

All values are calculated based on monomeric MCM subunit. For each value, standard error is given. Hill: Hill cooperativity coefficient.

ISSN: 1471-2199