DNA Replication l Replication initiation in Prokaryotes

DNA replication in prokaryotes begins at specific origins of replication (oriC), where the DnaA protein binds to conserved 9-base pair and 13-base pair sequences, causing positive supercoiling that denatures the AT-rich 13-base pair regions; this creates a replication bubble that recruits DnaB helicase (loaded by DnaC protein) to separate the DNA strands, with single-stranded binding proteins preventing re-annealing and topoisomerase II (DNA gyrase) relieving supercoiling ahead of the fork, ultimately allowing primase and DNA polymerase to initiate new strand synthesis.