Structural Studies of the Klentaq1 DNA Polymerase

DNA polymerase I enzymes have served as model systems to study the mechanism of template-directed DNA polymerization. This process requires that the enzyme cycles through a series of conformational changes, each cycle leading to the incorporation of a nucleotide to the primer strand of the DNA. The kinetics of nucleotide incorporation has been extensively studied leading to the definition of specific steps along the cycle. Efforts to visualize these steps using X-ray crystallography have recently come to fruition, notably for one particular DNA polymerase I system, that of Klentaq1. This review focuses on the structural characterization of the various steps along the nucleotide incorporation pathway.