DNA types of DNA pol which are DNA

DNA replication studies have been
conducted across Bacteria cells mainlyt because of the smaller size of the
genome and the mutants that are present in Bacteria cell. The E.coli bacteria
has 46 million base pairs in single chromosome and the replication takes
approximately 42 minutes which implicates that approximately 1000 nucleotides are
added every second in this replication process (Wendell et al. 2014). As the
process is very rapid there are a few errors within the process. For DNA
replication there is a large number of proteins and enzymes and the function of
each has been illustratred in the table below

Enzyme or Factor

Function

DNA pol I

This removes the RNA primer and further replaces it with
the DNA which has been synthesised

DNA pol III

This
is responsible for addition of nucleotides in 5′ and 3′ directions

Helicase

This is responsible for breaking the hydrogen bonds from
the nitrogen bases and thus opens the DNA helix

Ligase

It is
responsible for sealing the Okazaki fragments in order to create a continuous
DNA strand

Primase

This is responsible for synthesis of the RNA primer

Single-stranded binding proteins

This
prevents hydrogen bonding between the DNA strands by binding to the single
stranded DNA and further reforms double stranded DNA

Sliding clamp

This is beneficial in holding the DNAA pol III when the
nucleotides are added

Topoisomerase II (DNA gyrase)

Relaxes
the chromosome so that the DNA is nore accesible and initiates the
replication process. It also relieves the stres which the DNA goes through
during the unwinding process

Topoisomerase IV

This is responsible for introduction of single stranded
breaks in the chromosome and for resealing the DNA

 

In the DNA replication process one
of the most essential enzymes is the DNA polymerase or DNA pol. In case of
bacteria there are three types of DNA pol which are DNA pol I, DNA pol II and
DNA pol III. The DNA pol III is the major enzyme which is essential for the
synthesis of the DNA in the replication process. DNA pol I and DNA pol II are
mainly needed for the repair of the DNA. DNA pol III is responsible for the
addition of deoxyribonucleotides which are each complementary to a nuclotide in
the strand and this is done one at a time in the 3′-OH group (Bhattacharyya
et al. 2014). The addition of the nucleotides
requires energy and the energy is present in the triphosphate group which are
attached to each nucleotide. When the bond between this triphosphate group is
broken it accounts for release of energy and this is used for the synthesis of
the DNA. The entire DNA replication process has been illustrated through the
diagram below