DNA ligase is an enzyme that facilitates joining of DNA strands by catalyzing phosphodiester bond formation, playing a role in repairing single and double strand DNA breaks during replication and repair. Ribonuclease, also called RNase, is an enzyme that catalyzes degradation of RNA into smaller components and can be divided into endoribonucleases and exoribonucleases. Reverse transcriptase is an enzyme that generates complementary DNA from an RNA template through reverse transcription and is used by viruses like HIV and hepatitis B to replicate their genomes as well as for gene expression studies.

1. ENZYMES
N.CHITRA.
M.SC.,MICROBIOLOGY,
SPIHER.

2. DNA LIGASES :
➢ DNA ligase is a specific type of enzyme, that
facilitates the joining of DNA strands
together by catalyzing the formation of a
phosphodiester bond.
➢ It plays a role in repairing single-strand
breaks in duplex DNA in living organisms, but
some forms (such as DNA ligase IV) may
specifically repair double-strand breaks
➢ DNA ligase is used in both DNA repair and DNA
replication.

3. RIBONUCLEASE :
➢ It usually called as RNase.
➢ Ribonuclease is a type of nuclease that
catalyzes the degradation of RNA into
smaller components.
➢ Ribonucleases can be divided into
endoribonucleases and exoribonucleases.

4. REVERSE TRANSCRIPTASE :
➢ Reverse transcriptase (RTase) is an enzyme
used to generate complementary DNA (cDNA)
from an RNA template, a process termed
reverse transcription.
➢ Reverse transcriptases are used by certain
viruses such as HIV and the hepatitis B virus
to replicate their genomes.
➢ Also it is used for the specific gene
expression studies.