RNA Primer Removal in Bacterial DNA Replication

During bacterial DNA replication, RNA primers are synthesized to initiate DNA synthesis. These RNA primers must be removed and replaced with DNA.

Enzyme Responsible for Primer Removal

The enzyme responsible for removing RNA primers in bacteria is DNA Polymerase I. This is due to its specific enzymatic activities:

• 5' to 3' Exonuclease Activity: This allows DNA Polymerase I to remove the RNA nucleotides from the 5' end of the primer.
• 5' to 3' Polymerase Activity: After removing the RNA, DNA Polymerase I fills the resulting gap with DNA nucleotides.

Analysis of Options

• DNA gyrase: This enzyme (a topoisomerase) relieves torsional stress during replication but does not remove primers.
• DNA Polymerase I: Correctly identified as the enzyme with the necessary exonuclease and polymerase activity for primer removal and replacement.
• Primase: Synthesizes the RNA primer, it does not remove it.
• DNA Polymerase III: This is the main replicative polymerase responsible for synthesizing the bulk of the new DNA strand, but it lacks the specific exonuclease activity to remove RNA primers.

Therefore, DNA Polymerase I is the enzyme that removes the RNA primer synthesized during bacterial DNA replication.