What is the function of exonuclease?
Exonucleases are enzymes that work by cleaving nucleotides one at a time from the end (exo) of a polynucleotide chain. A hydrolyzing reaction that breaks phosphodiester bonds at either the 3′ or the 5′ end occurs.
What are endonucleases and Exonucleases?
An endonuclease is a group of enzymes that cleave the phosphodiester bond present within a polynucleotide chain. Exonucleases are enzymes that cleave DNA sequences in a polynucleotide chain from either the 5′ or 3′ end one at a time. Cleavage. Endonucleases cleave the nucleotide sequence from the middle.
What are types of endonucleases?
Restriction endonucleases (restriction enzymes) are divided into three categories, Type I, Type II, and Type III, according to their mechanism of action. These enzymes are often used in genetic engineering to make recombinant DNA for introduction into bacterial, plant, or animal cells, as well as in synthetic biology.
Can DNA replication occur without Primase?
Primase is required because DNA polymerases cannot initiate polymer synthesis on single-stranded DNA templates; they can only elongate from the 3′-hydroxyl of a primer. Primases fall into two major sequence and structure superfamilies: bacterial and eukaryotic nuclear.
What is the purpose of DNA polymerase III?
DNA Polymerase III, Bacterial The main function of the third polymerase, Pol III, is duplication of the chromosomal DNA, while other DNA polymerases are involved mostly in DNA repair and translesion DNA synthesis.
What are the 3 main stages of Semiconservative replication?
DNA replication steps. There are three main steps to DNA replication: initiation, elongation, and termination. In order to fit within a cell’s nucleus, DNA is packed into tightly coiled structures called chromatin, which loosens prior to replication, allowing the cell replication machinery to access the DNA strands.
What is replication process?
DNA replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules. Replication is an essential process because, whenever a cell divides, the two new daughter cells must contain the same genetic information, or DNA, as the parent cell.