9 terms

proteins and enzymes in bacterial replication

DNA polymerase III
primary replication enzyme - elongates a new nucleotide strand from the 3'- OH of the primer.
DNA polymerase I
removes the RNA nucleotides of the primers and replaces them with DNA nucleotides - carries out proofreading
DNA ligase
connects Okazaki fragments by sealing nicks in the sugar phosphate backbone
DNA primase
synthesizes the RNA primers that provide the 3' OH group needed for DNA polymerase III to initiate DNA synthesis
DNA helicase
unwinds the double helix by breaking the hydrogen bonding between the two strands at the replication fork
DNA gyrase
reduces DNA supercoiling and torsional strain that is created ahead of the replication fork by makine double-stranded breaks in the DNA and pasing another segment of the helix through the break before resealing it - also known as topoisomerase II
initiator proteins
bind to the replication origin and unwind short regions of DNA
single-stranded binding proteins (SSB protein)
stabilizes single-stranded DNA prior to replication by binding to it, thus preventing the DNA from pairing with complementary sequences
DNA polymerase II
functions as a DNA repair polymerase. restarts replication after DNA damage has halted replication and has proofreading activity