AP BIOLOGY

Detailed explanation-1: -T4 polynucleotide kinase (PNK) has become a widely used enzyme in the manipulation of polynucleotides since its discovery in 1965 (1–6). The most widely exploited function of PNK is its ability to catalyze the transfer of the -phosphate of a nucleoside triphosphate to the 5′-hydroxyl of a polynucleotide (1, 3, 7).

Detailed explanation-2: -DNA polymerase is the primary enzyme which catalyzes the linking of the 3′ hydroxyl group of the end nucleotide to the 5′ phosphate of nucleotide to be added.

Detailed explanation-3: -Typical amplification by PCR does not use phosphorylated primers. In this case, the 5’ ends of the amplicon are non-phosphorylated, and need to be treated by a kinase, such as T4 Polynucleotide Kinase, to introduce the 5’ phosphate.

Detailed explanation-4: -Polynucleotide kinase (PNK) is an enzyme that catalyzes the reversible phosphorylation of nucleoside monophosphates, ss and ds nucleic acids.

Detailed explanation-5: -T4 Polynucleotide Kinase catalyzes the transfer of the -phosphate from ATP to the 5´-terminus of polynucleotides or to mononucleotides bearing a 5´-hydroxyl group. The enzyme may be used to phosphorylate RNA, DNA and synthetic oligonucleotides prior to subsequent manipulations such as ligation and cloning.