Which protein stabilizes the single-stranded DNA after unwinding?

Which protein stabilizes the single-stranded DNA after unwinding?

• A. DNA polymerase
• B. Single-strand binding proteins
• C. Topoisomerase
• D. Helicase

Answer: (B)

After DNA unwinds, the exposed single-stranded DNA is prone to reannealing and damage. Single-strand binding proteins coat the ssDNA, keeping it stretched out and protected, which prevents secondary structures and nuclease attack and also keeps it accessible for replication or repair enzymes. That stabilization is what allows the DNA polymerase and other machinery to operate smoothly on a ready template. DNA polymerase would synthesize new DNA rather than just stabilize the strand. Topoisomerase relieves torsional stress from unwinding, and helicase is the enzyme that does the unwinding in the first place. So the protein that stabilizes the single-stranded DNA is the single-strand binding protein.

After DNA unwinds, the exposed single-stranded DNA is prone to reannealing and damage. Single-strand binding proteins coat the ssDNA, keeping it stretched out and protected, which prevents secondary structures and nuclease attack and also keeps it accessible for replication or repair enzymes. That stabilization is what allows the DNA polymerase and other machinery to operate smoothly on a ready template. DNA polymerase would synthesize new DNA rather than just stabilize the strand. Topoisomerase relieves torsional stress from unwinding, and helicase is the enzyme that does the unwinding in the first place. So the protein that stabilizes the single-stranded DNA is the single-strand binding protein.