1tgo
From Proteopedia
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THERMOSTABLE B TYPE DNA POLYMERASE FROM THERMOCOCCUS GORGONARIUS
Overview
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 A resolution, crystal structure of a DNA polymerase from the Archaea Thermococcus, gorgonarius and identify structural features of the fold and the active, site that 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 bonds and an enhanced electrostatic complementarity at the, DNA-protein interface. In contrast to gp43, several loops in the, exonuclease and thumb domains are more closely packed; this apparently, blocks primer binding to the exonuclease active site. A physiological role, of this "closed" conformation is unknown but may represent a polymerase, mode, in contrast to an editing mode with an open exonuclease site. This, archaeal B DNA polymerase structure provides a starting point for, structure-based design of polymerases or ligands with applications in, biotechnology and the development of antiviral or anticancer agents.
About this Structure
1TGO is a Single protein structure of sequence from Thermococcus gorgonarius. Active as DNA-directed DNA polymerase, with EC number 2.7.7.7 Full crystallographic information is available from OCA.
Reference
Crystal structure of a thermostable type B DNA polymerase from Thermococcus gorgonarius., Hopfner KP, Eichinger A, Engh RA, Laue F, Ankenbauer W, Huber R, Angerer B, Proc Natl Acad Sci U S A. 1999 Mar 30;96(7):3600-5. PMID:10097083
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