Accessory Proteins for DNA Replication

DNA Ligase

Creates phosphodiester bonds between Okazaki fragments on the lagging strand
-catalyzes the formation of phosphodiester bonds between DNA Fragments

DNA Polymerases I

Removes the RNA primers and replaces them with DNA nucleotides

DNA Polymerase III

Synthesizes the new strands, but it requires an existing 3' hydroxyl
(-OH) group to add new nucleotides.
- Starts DNA synthesis at the 3' end of a primer


Breaks the hydrogen bonds between the parental DNA strands and
unwinds the double helix.
- Breaks the hydrogen bonds that hold the parental DNA strands together


Creates short RNA primers, initiating DNA synthesis on both template strands
- Synthesizes short sequences of RNA required for DNA replication

Single strand biding proteins

Bind to the single strands of DNA, preventing them from reforming
hydrogen bonds
- coats the separated DNA strands


cuts, swivels, and rejoins DNA stands ahead of the replication fork
- Relaxes supercoiled DNA by catalyzing the controlled cleavage and
rejoining of DNA