Which enzyme will digest RNA in a DNA-RNA Hybrid?
Which enzyme will digest RNA in a DNA-RNA Hybrid?
Select an option to attempt
Correct Answer: Option D
Explanation
RNase H: enzyme that digests RNA in a DNA:RNA hybrid:RNase H (Ribonuclease H) is an endonuclease with specific activity against the RNA strand of an RNA:DNA heteroduplex:• It cleaves the RNA strand internally (5'→3' and 3'→5') but does NOT degrade single-stranded RNA or double-stranded DNA.• Biological roles: During reverse transcription (retroviruses, retrotransposons), after first-strand cDNA is made, the RNA template must be removed so that second-strand synthesis can occur — RNase H does this.• Also functions during DNA replication to remove RNA primers (e.g., Okazaki fragment primers) in some organisms.Distractors:• RNase A: degrades single-stranded RNA, not RNA:DNA hybrids.• BamHI: a DNA restriction endonuclease.• Reverse transcriptase: has intrinsic RNase H activity but IS reverse transcriptase, not a standalone nuclease.Answer: RNase H (Option 4).