How many types of dna polymerase enzymes are there?
A DNA polymerase is an enzyme that catalyzes the polymerization of deoxyribonucleotides into a DNA strand. DNA polymerases are best-known for their role in DNA replication, in which the polymerase “reads” an intact DNA strand as a template and uses it to synthesize the new strand. This process copies a piece of DNA. The newly-polymerized molecule is complementary to the template strand and identical to the template’s original partner strand. DNA polymerases use a magnesium ion for catalytic activity. Bacteria have 5 known DNA polymerases: Pol I: implicated in DNA repair; has 5′->3′ (Polymerase) activity and both 3′->5′ exonuclease (Proofreading) and 5′->3′ exonuclease activity (RNA Primer removal). Pol II: involved in reparation of damaged DNA; has 3′->5′ exonuclease activity. Pol III: the main polymerase in bacteria (elongates in DNA replication); has 3′->5′ exonuclease proofreading ability. Pol IV: a Y-family DNA polymerase. Pol V: a Y-family DNA polymerase; participates in bypassing
