Mutation S543N in the thumb subdomain of the Taq DNA polymerase large fragment suppresses pausing associated with the template structure

Substitution of Asn for the conserved Ser(543) in the thumb subdomain of th e Tag DNA polymerase large fragment (Klentaq DNA polymerase) prevents pausi ng during DNA synthesis and allows the enzyme to circumvent template region s with a complex structure. The mutant enzyme (Klentaq(N) DNA polymerase) p rovides specific PCR amplification and sequencing of difficult templates, e .g. those with a high GC% content or strong secondary structure. (C) 1999 F ederation of European Biochemical Societies.