Protein Used in DNA Replication

DnaA

issue: unwinding of helix

function: binds to ORI causing conformation change

Helicase

issue: unwinding of helix

function: opens and recruits holoenzyme to bind replication form and initiate replication

SSBPs

issue: prevent the helix from reforming

function: stabilizes the open helix and binds to single strands of DNA

primase

issue: synthesis of primer for initiation

function: makes the RNA primers for elongation

DNA Poly III

issue: continuous synthesis

function: main enzyme that adds nucleotides in the 5’ to 3’ direction in both strandsD

DNA Poly I

issue: discontinuous synthesis and removal of the RNA primers

function: removes RNA primer on the lagging strand and replaces it with newly synthesized DNA; removes primers on lagging strand

DNA ligase

issue: joining of gap-filling DNA

function: seals nicks and joins Okazaki fragments

DNA gyrase

issue: reduce increased coiling

function: enzyme relieves coiled tension from unwinding of helix

DNA Poly I & III

issue: proofreading

function: double-checks the newly synthesized DNA for errors