What is the structure of DNA polymerase molecules?

DNA polymerases share a common structural framework composed of subdomains known as the palm, fingers, thumb, N terminus, and exonucleases. The fingers play a key role in recognizing and binding nucleotides, while the thumb is responsible for DNA substrate binding. The palm holds crucial amino acids vital for catalysis in its active sites. Between the fingers and thumb, there's a pocket comprising two regions: the insertion site and post-insertion site. Incoming nucleotides bind to the insertion site, and the new base pair is situated in the post-insertion site. It is important to note each polymerase family has unique variations in these structures. The N-terminus is composed of nonadjacent portions of amino acids. Positioned between the thumb and N terminus, the exonuclease subdomain aids in correcting errors. When an incorrect nucleotide is added, the polymerase guides the primer terminus toward the exonuclease subdomain. A conserved motif, surrounded by β-sheets and α helices, acts as the active site here.