Question

Match LIST-I with LIST-II
\begin{tabularx}{0.9\textwidth}{|l|X|l|X|} \hline \multicolumn{2}{|c|}{LIST-I} & \multicolumn{2}{c|}{LIST-II}
\multicolumn{2}{|c|}{Replication Enzymes in E coli} & \multicolumn{2}{c|}{Replication Enzymes in Human}
\hline A. & \(\beta\)-clamp & I. & RPA
B. & SSB & II. & PCNA
C. & Gyrase & III. & DNA polymerase alpha
D. & DnaG & IV. & Topo-I, II
\hline \end{tabularx}
Choose the most appropriate answer from the options given below:

• A. A - I, B - II, C - III, D - IV
• B. A - I, B - III, C - II, D - IV
• C. A - I, B - II, C - IV, D - III
• D. A - II, B - I, C - IV, D - III

Hint:

To remember the sliding clamps: think of the Greek letter Beta (\(\beta\)) for \textbf{B}acteria ({E. coli}) and PCNA, which sounds like a clinical term, for more complex organisms like humans.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
This question requires matching key DNA replication proteins from a prokaryote ({E. coli}) with their functional homologs in a eukaryote (Human). Although the specific proteins have different names, their roles in the replication process are conserved.

Step 2: Detailed Matching:
- A. \(\beta\)-clamp: In {E. coli}, this is the sliding clamp protein that encircles the DNA and holds the DNA polymerase onto the template, ensuring high processivity. Its human counterpart is PCNA (Proliferating Cell Nuclear Antigen). Thus, A matches with II.
- B. SSB (Single-Strand Binding protein): In {E. coli}, SSB binds to the separated single strands of DNA to prevent them from reannealing and to protect them from degradation. The human homolog is RPA (Replication Protein A). Thus, B matches with I.
- C. Gyrase: This is a type II topoisomerase in {E. coli} that relieves the torsional strain created by helicase unwinding. In humans, this function is performed by Topoisomerases I and II (Topo-I, II). Thus, C matches with IV.
- D. DnaG: This is the primase enzyme in {E. coli} that synthesizes short RNA primers to initiate DNA synthesis. In humans, the primase is part of a complex along with DNA polymerase alpha, which synthesizes the primer and then extends it with a short stretch of DNA. Thus, D matches with III.

Step 3: Final Answer:
The correct set of matches is A-II, B-I, C-IV, D-III. This corresponds to option (D).