AP BIOLOGY

Detailed explanation-1: -S1 nuclease (from Aspergillus oryzae) is a specific enzyme to degrade single stranded DNA or RNA molecules. It has been reported to be able to convert superhelical circular DNA molecules into open circle or linear forms under certain conditions, but this function has not been well explored.

Detailed explanation-2: -S1 nuclease mapping is a nuclease protection assay using nuclease S1. This technique is used to quantify and map RNA transcripts. It is capable of identifying individual RNAs in a mixture of RNA sample of known sequence. It can particularly map introns and 5′ and 3′ ends of transcribed gene regions.

Detailed explanation-3: -Another way to find the start of transcription is by hybridizing the mRNA to the corresponding DNA and cutting away the single-stranded overhangs with S1 nuclease. The single-stranded DNA fragment is labeled on its 5′ end and then denatured and hybridized to the corresponding mRNA (Fig.

Detailed explanation-4: -Nucleases are enzymes that degrade nucleic acids. These are categorized as ribonucleases (RNases) that attack RNA and deoxyribonucleases (DNases) that attack DNA. Most nucleases are specific, though the degree of specificity varies greatly.