Final answer:
In bacterial DNA replication initiation, a combination of initiator proteins and enzymes such as topoisomerase II (DNA gyrase) and helicase bind to the oriC to introduce a 'bend' and unwind the DNA, making it accessible for replication.
Step-by-step explanation:
DNA replication begins at specific regions of the chromosome called origins of replication. During initiation of DNA replication in bacteria, a complex of proteins binds to the chromosome at the oriC.
This protein complex includes initiator proteins that recognize the oriC sequence. Additionally, enzymes like topoisomerase II, also known as DNA gyrase, and helicase play crucial roles.
DNA gyrase helps in relaxing the supercoiled chromosome, allowing helicase to introduce a single-stranded 'bend' by breaking the hydrogen bonds between base pairs, creating single-stranded regions necessary for replication to commence.