CRYSTAL STRUCTURE OF KLENOW-ANALOGOUS FRAGMENT OF THERMUS AQUATICUS DNA POLYMERASE I AT 2.5Å RESOLUTION. Sergey Korolev, Murad Nayal, Wayne M. Barnes, Enrico Di Cera, and Gabriel Waksman. Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, MO 63110, USA

The crystal structure of the large fragment of the Taq DNA polymerase (Klentaq1), determined at 2.5Å resolution, demonstrates a compact, two domain architecture. The C-terminal domain is identical in fold to the equivalent region of the Klenow fragment of Escherichia coli DNA polymerase I (Klenow Pol I). Although the N-terminal domain differs greatly in sequence from its counterpart in Klenow Pol I, it has clearly evolved from a common ancestor. The structure of Klentaq1 reveals the strategy utilized by this protein to maintain activity at high temperatures and provides the structural basis for future improvements of the enzyme.

Ref:

S. Korolev et al., (1995) Proc. Natl. Acad. Sci. USA 92, 9264-9268.