Discussion
Which one of the following statements about the DNA polymerase III of E. coli is NOT correct?
Answer: A
The statement that is NOT correct is it catalyzes nick translation.
Nick translation needs a 5′ → 3′ exonuclease working ahead of the polymerase, removing nucleotides from the 5′ end at a nick while new ones are added at the 3′ end. That combination belongs to DNA polymerase I, which uses it to remove RNA primers. DNA polymerase III has no 5′ → 3′ exonuclease.
The other statements are true of polymerase III. It is the main replicative enzyme, so losing it is lethal. It copies a single-stranded template into a complementary strand, extending a primer. Its ε subunit carries 3′ → 5′ exonuclease activity, which proofreads misincorporated bases.
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development