Table 2.

Fidelity of pol λ DL in the forward assay

	Pol λ DL	Pol λ wt
Mutant frequency × 10−2	54a	21b
Mutants sequenced	50	103
Nucleotides sequenced	20 350	41 921
Total changes	618	253

Classes	Error rate × 10−4
Base substitutions	120 (252)	9 (38)
1-nt deletions	120 (239)	45 (190)
2-nt deletions	5.9 (12)	2.1 (9)
1-nt additions	3.4 (7)	1.6 (7)
Other changesc	(108)	(9)

The number of occurrences is given in parenthesis.

^aThe mutant frequency of pol λ DL represents one of seven independent determinations. The other six mutant frequencies were 43 × 10⁻², 48 × 10⁻² and 37 × 10⁻² (reactions with 150 nM pol λ DL at pH 7.5), 39 × 10⁻² and 50 × 10⁻² (reactions with 50 nM pol λ DL at pH 8.5), 54 × 10⁻² (reaction with 150 nM pol λ DL at pH 8.5).

^bThe stated mutant frequency of pol λ wt, determined at the same time as the mutant frequency of pol λ DL, is identical to that reported earlier (39). The specificity of pol λ wt is from (39).

^cClassified as ‘other changes’ are large deletions and complex errors involving substitution-deletion and substitution-addition errors.