Crystal structure of a thermostable type B DNA polymerase from Thermococcus gorgonarius

Citation
Kp. Hopfner et al., Crystal structure of a thermostable type B DNA polymerase from Thermococcus gorgonarius, P NAS US, 96(7), 1999, pp. 3600-3605
Citations number
48
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Multidisciplinary
Journal title
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
ISSN journal
0027-8424 → ACNP
Volume
96
Issue
7
Year of publication
1999
Pages
3600 - 3605
Database
ISI
SICI code
0027-8424(19990330)96:7<3600:CSOATT>2.0.ZU;2-Y
Abstract
Most known archaeal DNA polymerases belong to the type B family, which also includes the DNA replication polymerases of eukaryotes, but maintain high fidelity at extreme conditions. We describe here the 2.5 Angstrom resolutio n crystal structure of a DNA polymerase from the Archaea Thermococcus gorgo narius and identify structural features of the fold and the active site tha t are likely responsible for its thermostable function. Comparison with the mesophilic B type DNA polymerase gp43 of the bacteriophage RB69 highlights thermophilic adaptations, which include the presence of two disulfide bond s and an enhanced electrostatic complementarity at the DNA-protein interfac e. In contrast to gp43, several loops in the exonuclease and thumb domains are more closely packed; this apparently blocks primer binding to the exonu clease active site. A physiological role of this "closed" conformation is u nknown but may represent a polymerase mode, in contrast to an editing mode with an open exonuclease site. This archaeal 13 DNA polymerase structure pr ovides a starting point for structure-based design of polymerases or ligand s with applications in biotechnology and the development of antiviral or an ticancer agents.