A. DNA release
B. Cleavage and opening of gate
C. Rejoining of cleaved strand
D. Strand passage
Choose the correct answer from the options given below :
Understanding Type I Topoisomerase DNA Relaxation Mechanism
Type I topoisomerases function to relax supercoiled DNA by transiently breaking and rejoining one DNA strand. This process involves several key steps performed in a specific order.
Sequence of DNA Relaxation
The mechanism proceeds as follows:
- B. Cleavage and opening of gate: The enzyme initially binds to the DNA and introduces a temporary single-strand break (nick). This cleavage event allows the enzyme to create an opening or 'gate' in the DNA backbone.
- D. Strand passage: Through this gate, the intact, opposite DNA strand passes. This passage alters the DNA's topological state.
- C. Rejoining of cleaved strand: Following the passage of the intact strand, the enzyme reseals the nicked DNA strand, restoring the phosphodiester backbone.
- A. DNA release: Finally, the type I topoisomerase detaches from the DNA molecule, leaving it in a relaxed state.
Therefore, the correct sequence representing the action of type I topoisomerase in DNA relaxation is B → D → C → A.
Similar Questions
- What is the concentration of $OH^-$ in a solution with an $H^+$ concentration of $2 \times 10^{-4} M$ ? The ion product of water at 25$^\circ$ C is $1.0 \times 10^{-14} M^2$.
- Choose the correct sequence from the option for evolution of pathologic hypertensive arteriolosclerosis.
A. Increase in Extra cellular matrix (ECM), smooth muscle proliferation
B. Vascular injury from malignant hypertension
C. Stress (haemodynamic, metabolic)
D. Increase in Permeability, leakage of plasma components
Choose the correct answer from the options given below : - Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : If the device is left out on the worktable "faint ghost band" appears at the test region.
Reason (R) : The unbound conjugate deposited on the test band results in appearance of a faint ghost band.
In the light of the above statements, choose the most appropriate answer from the options given below : - Match List - I with List - II.
List - I (Organism) List - II (Telomere repeat sequence) A. Human I. $(TTGGGG)_n$ B. Yeast II. $(TTTAGGG)_n$ C. Plant III. $((TG)_{1-3}(TG)_{2-3})_n$ D. Ciliated Protozoan IV. $(TTAGGG)_n$
Choose the correct answer from the options given below : - The amount of blood in an average adult human is _________.
- Arrange DNA crossover between two identical circular molecules from recombination site to final stage.
A. DNA replication
B. Complete DNA replication
C. Site-specific recombination
D. Homologous recombination
Choose the correct answer from the options given below : - The ability to construct recombinant DNA molecules and maintain them in cells is called _________.
- Match List - I with List - II.
List - I (Morphology) List - II (Functions) A. Mitochondria I. Breakdown of macromolecules for catabolism B. Cytoskeleton II. Main site for synthesis of new proteins or polypeptides C. Lysosomes III. Shape and support to cell D. Ribosomes IV. Energy generation by ATP synthesis
Choose the correct answer from the options given below : - The ability of a malignant cell to detach itself from a tumor and establish a new tumor and another site within the host :
- Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : Cells of different tissues essentially require $CO_2$ to generate energy and perform metabolic functions.
Reason (R) : Deficiency of oxygen or hypoxia results in failure to carry metabolic functions.
In the light of the above statements, choose the most appropriate answer from the options given below :
Important Questions from Mixed Topic (CUET PG)
- Who was the founder of Bolshevik Communist party?
- What is the key guide to statecraft in the realist tradition?
- Chronologically arrange the events in the Cold War period.
A. Berlin Wall is constructed
B. Communist China joins the UN
C. Soviet invasion of Czechoslovakia
D. Berlin Blockade
Choose the correct answer from the options given below: Morgenthau's principles of political realism are:
A. Politics is rooted in permanent and unchanging human nature which is basically self centred, self-regarding and self-interested
B. Politics is an autonomous sphere of action and cannot therefore be reduced to morals
C. International Politics is an arena of conflicting self-interests
D. The ethics of international relations is situational ethics which is very different from private morality
Choose the correct answer from the options given below:Who among the following political thinkers consider the anarchical self help system to be a compelling factor for States to maximise their relative power positions?
