Final answer:
DNA replication in prokaryotes like E. coli starts at the oriC, an AT-rich segment. Helicase unwinds the DNA to form replication forks, with single-strand binding proteins and DNA polymerase III playing crucial roles in the creation of new DNA strands.
Step-by-step explanation:
In prokaryotic organisms such as E. coli, the process of DNA replication begins at a specific section of the chromosome known as the origin of replication, or oriC. This segment is identifiable by its AT-rich sequences and is approximately 245 base pairs long. Proteins responsible for recognizing this site and commencing DNA replication include a helicase, which is a hexameric enzyme that unwinds the DNA helix by breaking the hydrogen bonds between nitrogenous bases.
Once the double helix is opened by helicase, Y-shaped structures called replication forks are established. These forks extend bidirectionally from the origin as replication progresses. Single-strand binding proteins (SSBs) stabilize the unwound DNA strands, preventing them from reannealing. Primase synthesizes a short RNA primer needed by DNA polymerase III to start the synthesis of the new DNA strand. Replication continues with the aid of other enzymes until two complete daughter strands are formed.