Accessory proteins:

DNA polymerases I and III primase and DNA ligase are not the only proteins required for replication of the bacterial chromosome.  The  DNA  sample  is  a double  helix  with  every  strand  wound  tightly  around  the other  and hence  the two  strands  must  be  unwound in  during  replication.   How is this unwinding problem resolve?  The  DNA  helicase is  used  to  unwind  the double helix (using ATP as energy source) and SSB (single-stranded  DNA- binding)  protein  prevents  the single-stranded  regions  from base pairing again so in which each of the two DNA strands is accessible for replication. In standard, for a replication fork to move along a piece of DNA the DNA helix would require to unwind ahead of it causing the DNA to rotate rapidly. Moreover, the bacterial chromosome is circular and so there are no ends to rotate. The solution  to the problem  is  in which  an  Enzyme  called  topoisomerase I breaks  a  phosphodiester bond in one DNA strand (a single-strand  break) a small distance  ahead of the fork, permitting the DNA to rotate freely (swivel) around the other intact strand. The phosphodiester bond is then re-formed through the topoisomerase.

When the bacterial circular DNA has been replicated the result is two double- stranded circular DNA molecules which are linked.  The Topoisomerase II separates them as follows. This enzyme works in a same manner to topoisomerase I but causes a transient break in every strand (a double-strand break) of a double-stranded DNA molecule. Therefore topoisomerase  II binds to one double-stranded DNA  causes and circle  a  transient  double-strand  break  which acts as a 'gate' by that the other DNA circle can pass. The Topoisomerase II then re-seals the strand breaks.

figure:  Separation of daughter DNA circles by topoisomerase II.