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. Author manuscript; available in PMC: 2012 Feb 8.

Published in final edited form as: Biochemistry. 2011 Jan 11;50(5):618–627. doi: 10.1021/bi102046h

Table 2.

Kinetic parameters of hUNG2, hSMUG1, and hTDG on 5-FU (F) and U containing DNA substrates.^a

	hUNG2		hSMUG1			hTDG^b

Substrate	k_cat (min⁻¹)	K_m (µM)	k_cat (min⁻¹)	K_m (µM)	k_max (min⁻¹)	k_cat (min⁻¹)	K_m(µM)	k_max(min⁻¹)
ssU	2193 ± 39	15 ± 1	5.6 ± 0.1	12 ± 1	≥ 5.6	NA	NA	NA
U•G	830 ± 30	3.3 ± 0.3	7.0 ± 0.3	1.8 ± 0.3	209 ± 16	0.005 ± 0.001	~ 0.01	2.2 ± 0.3
U•A	171 ± 5	3.3 ± 0.2	0.39 ± 0.01	0.40 ± 0.02	14 ± 1	ND	ND	0.0033 ± 0.0001
ssF	90 ± 4	64 ± 5	< 0.1	~ 10 – 20	ND	ND	ND	~ 1^c
F•G	51 ± 2	32 ± 3	0.48 ± 0.02	0.7 ± 0.1	40 ± 6	0.63 ± 0.17	0.039 ± 0.008	278 ± 35
F•A	39 ± 2	39 ± 5	< 0.1	~ 1	0.7 ± 0.1	ND	ND	1.08 ± 0.08

^a

ND, not determined; NA, no activity. The indicated k_max values are single-turnover rate constants.

^b

Kinetic properties of hTDG were previously reported (14, 15)

^c

Alexander Drohat; personal correspondence, 2010