DNA polymerase is an enzyme that synthesizes DNA molecules from deoxyribonucleotides, the building blocks of DNA. These enzymes are essential for DNA replication and usually work in pairs to create two identical DNA strands from a single original DNA molecule. During this process, DNA polymerase “reads” the existing DNA strands to create two new strands that match the existing ones.
|DNA Replication||original DNA strands are used as templates for the synthesis of new strands|
|Okazaki fragments||fragments (1000-2000 nucleotides in bacteria, 100-200 in eukaryotes) that consist of a short RNA primer at the 5′ end made by primase, and a strand of DNA made by polymerase 3. Located on the lagging strand.|
|DnaA proteins||initiate replication by binding to DnaA box sequences within the origin. Can only bind when they are in their ATP bound form, and they bind to 5 DnaA boxes in oriC to initiate replication. Also bind to each other to form a complex.|
|DnaA complex||Formed from DnaA proteins binding to each other. With the aid of other SNA-binding proteins (such as HU and IHF), this causes the DNA to bend around the complex of DnaA proteins and results in the separation of the AT-rich region.|
|DNA polymerase||Synthesizes DNA of the leading and lagging strands. Catalyzes the formation of covalent bonds between adjacent nucleotides to make new daughter strands.|
|DNA polymerase in E.coli||I-V, polymerase I and III are involved in normal replication and II, IV, and V play a role in the repair and replication of damaged DNA.|
|DNA polymerase I (e.coli)||The role is to remove RNA primers and fill in the vacant regions with DNA. Composed of a single subunit|