Question

List proteins (enzymes and other factors) involved in the process of DNA replication in E. coli. Explain briefly the role of each of these proteins in replication.

A) DNA helicase - unwinds the DNA; DNA polymerase - repairs damaged DNA.
B) DNA ligase - joins Okazaki fragments; DNA topoisomerase - prevents supercoiling.
C) Primase - synthesizes RNA primers; DNA gyrase - proofreads DNA.
D) Telomerase - adds telomeres; RNA polymerase - initiates transcription.

Answer 1

In DNA replication of E. coli, proteins such as DNA helicase, DNA topoisomerase, primase, DNA polymerase III, and DNA ligase, play crucial roles ranging from unwinding DNA to sealing DNA fragments, ensuring the precise duplication of genetic material.

Step-by-step explanation:

The process of DNA replication in E. coli involves various enzymes and factors, each with a specific role:

• DNA helicase unwinds the DNA at the origin of replication.
• DNA topoisomerase (also referred to as DNA gyrase in prokaryotes) alleviates supercoiling ahead of the replication fork.
• Single-stranded binding proteins stabilize the unwound strands of DNA to prevent premature reannealing.
• Primase synthesizes short RNA primers needed for DNA polymerase to begin replication.
• DNA polymerase III is the primary enzyme that adds nucleotides to the growing DNA strand.
• DNA ligase seals the Okazaki fragments on the lagging strand to create a continuous strand.

These proteins and enzymes work in a coordinated manner to ensure precise replication of the bacterial genome prior to cell division.