Table 1.

Rate constants for sequential ligation by LIG3β^a

k obs (min−1)	Blunt-end	3′-DSB	5′-DSB
First ligation	3.2 ± 0.2	1.6 ± 0.5	2.6 ± 0.3
Second ligation	4.9 ± 0.3	2.3 ± 0.2	2.4 ± 0.1
Steady-stateb	0.058 ± 0.012	0.13 ± 0.01	0.11 ± 0.01

^aObserved single-turnover rate constants for reactions of 20 nM LIG3β and 40 nM EJ substrates in the presence of 1 mM free Mg²⁺ and 10% PEG (Figure 5C).

^bAveraged k_cat values for reactions of 1 and 2 nM LIG3β with 20 and 40 nM EJ substrates, respectively. Reactions contained 1 mM free Mg²⁺ and 10% PEG (Figure 5A).