Effect of N3-Methyladenine and an Isosteric Stable Analogue on DNA Polymerization

Figure 8

Extension from (A) c³A⋅N and (B) 3-m-c³A⋅N by T7 Sequenase. The template strand containing a c³A or 3-m-c³A at A-27 was annealed to a 5^-Cy5-primer (Table 1, P27). T7 Sequenase was added and the reactions initiated by the addition of the individual dNTP’s. Extension is most efficient from c³A⋅T termini, while extension is similar from the 3-m-c³A⋅T and 3-m-c³A⋅G. Note that for 3-m-c³A⋅G only one dGTP is added rather than the two observed for 3-m-c³A⋅T.

(a)

(b)