DNA Polymerase 1 vs. DNA Polymerase 3

Human DNA is a complicated source, and people who do not belong to the field cannot have all the information about everything. Therefore, this article defines the two most important parts of the enzymes present within the DNA and they are DNA Polymerase 1 and DNA Polymerase 3. The main difference between these two is as follows. DNA Polymerase 1 gets known as an enzyme present in the human DNA that contributes towards the process of DNA replication. DNA Polymerase 3 gets referred to as the primary protein found in the human DNA that contributes towards the process of DNA replication.

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DNA Polymerase 1 vs. DNA Polymerase 3

Contents: Difference between DNA Polymerase 1 and DNA Polymerase 3

Comparison Chart

Basis of DistinctionDNA Polymerase 1DNA Polymerase 3
DefinitionOne of the enzymes that contributes towards the process of DNA replication.The most critical enzyme that contributes towards the process of DNA replication.
DiscoveryDiscovered by Arthur Kornberg in 1956.Created in the 1970’s by Thomas Kornberg and Malcolm Gefer.
RoleCrucial for eliminating of the RNA primers from the fragments and substituting it with the obligatory nucleotidesNecessary for the replication of the leading and the lagging strands.
FunctionDNA labeling by nick translation and second strand synthesis of cDNA.Replication of the leading and the lagging strands.
ActivityBoth the 3’ – 5’ and 5’ – 3’ exonucleases activitiesOnly 3’- 5’ exonucleases activity.
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What is DNA Polymerase 1?

It is known as an enzyme discovered in the human DNA that contributes towards the process of DNA replication. Initially, it got referred to as the DNA polymerase since it was first of the kind but then after the discovery of other types in the same category, it changed the name to DNA Polymerase 1. Discovered by Arthur Kornberg in 1956 it has the characteristics of E. coli because of the particular gene that encodes the Pol I and known as polA. DNA polymerase 1 is indispensable for eliminating of the RNA primers from the fragments and substituting it with the obligatory nucleotides. This section came into discovery when Arthur and his term worked on the extracts of DNA Synthesis array. Another function it performs is the repair of the damaged parts of human DNA. They also play a role in DNA replication. Here the leading DNA strand is continuously extended in the direction of repetition fork movement; whereas, the DNA lagging strand runs intermittently in the opposite direction as Okazaki fragments. They perform four different enzymes activities, the first one gets known as the A 5’-3’ that needs DNA-Dependent DNA polymerase activity, requiring a 3′ primer site and a template strand. When we talk about the second one is A 3’-5’ that has exonucleases activities to control the proofreading. The third function is 5’-3’ forward exonuclease activity that helps in nick translation during the process of repairing the DNA. Last is the A 5’-3’ forward RNA-dependent DNA polymerase activity. They have several applications such as use in the molecular biology research but gets unstable for working under most conditions.

What is DNA Polymerase 3?

It is known as the primary enzyme present in the human DNA that contributes towards the process of DNA replication. Discovered in the 1970’s by Thomas Kornberg and Malcolm Gefer it has a high level of nucleotides that get added at every binding unit and the replication of the E. coli genome that works with four other DNA polymerases. DNA polymerase 3 is important for the replication of the leading and the lagging strands. Since it is the primary enzyme in the DNA, therefore, has the proofreading facility that helps in removing any mistakes that occur during the repairing process. Some of the main components of it are as follows. 2 DNA Pol III enzymes, each comprising α, ε and θ subunits. The first one performs the polymerase activity, the second one shows the exonuclease activity, and the last one stimulates the proofreading process. Next part is the two β units that act as sliding DNA clamps and keep the part connected with the DNA. The other part is the two τ units that have the primary function of dimerizing the two critical enzymes. One γ unit that acts as the leader of the clamp and helps the two β subunits to form a unit and bind to DNA. It also creates pairs at a fast speed; this ranges around 1000 nucleotides in each second. The activity begins after the strands get separated near the place of replication. After the completion of this process, all the RAN primer get removed from the DNA polymerase I from the process of nick translation. Lastly, it is not considered essential for Clo DF13 replication.

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Key Differences between DNA Polymerase 1 and DNA Polymerase 3

  1. DNA Polymerase 1 gets known as an enzyme present in the human DNA that contributes towards the process of DNA replication. DNA Polymerase 3 gets referred to as the primary protein found in the human DNA that contributes towards the process of DNA replication.
  2. DNA polymerase 1 is indispensable for eliminating of the RNA primers from the fragments and substituting it with the obligatory nucleotides. On the other hand, DNA polymerase 3 is important for the replication of the leading and the lagging strands.
  3. Discovered by Arthur Kornberg in 1956 DNA polymerase 1 has the characteristics of E. coli because of the particular gene that encodes the Pol I and known as polA. Discovered in the 1970’s by Thomas Kornberg and Malcolm Gefer DNA polymerase 3 has a high level of nucleotides that get added at every binding unit and the replication of the E. coli genome.
  4. The primary function of DNA polymerase 1 is DNA labeling by nick translation and second strand synthesis of cDNA. On the other hand, DNA polymerase 3 is essential for the replication of the leading and the lagging strands.
  5. The DNA polymerase 1 has both the 3’ – 5’ and 5’ – 3’ exonucleases activities whereas the DNA polymerase 3 has only 3’- 5’ exonucleases activities.

Video Explanation

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