In addition to polymerase activity, this DNA polymerase exhibits 3' to 5' exonuclease activity. Intein encoded endonucleases are thought to mediate intein mobility by site-specific recombination initiated by endonuclease cleavage at the 'homing site' in gene that lack the intein. a 2'-deoxyribonucleoside 5'-triphosphate + DNA(n) = diphosphate + DNA(n+1) This protein undergoes a protein self splicing that involves a post-translational excision of the two intervening regions (inteins) followed by peptide ligation. Used in the PCR method because of its high thermostability and low error rate. Sold by New England Biolabs. Belongs to the DNA polymerase type-B family.