Polymerization of Nucleotides (Phosphodiester Bonds)
Nucleic acid polymers can be extremely long molecules, and therefore, difficult to manupulate and sequence. Similarly, it may be desirable to rearrange regions within a polynucleotide, or insert or delete specific regions. All these processes require the ability to selectively hydrolyze phosphodiester bonds within the polynucleotide molecule
Phosphodiester bond, Legame fosfodiesterico, , , ..
In phosphodiester , water is dissociated into H+ and OH-. The OH- acts as a in the reaction. The reaction is catalysed by .
The mechanism of this reaction is given below.
When pyrophosphate is cleaved by the addition of water, a great deal of free energy is released, ensuring that the reverse process (hydrolysis of the phosphodiester bond to give free nucleotides) is very unlikely to occur.
DNA nucleotides and dehydration synthesis Glycoside bond
100-200 nucleotides long and found in eukaryotic nuclei in complex with specific proteins, forming small nuclear ribonucleoprotein particles (RNA has Uracil Hydrolysis of Nucleic AcidsNucleic acid polymers can be extremely long molecules, and therefore, difficult to manupulate and sequence. Similarly, it may be desirable to rearrange regions within a polynucleotide, or insert or delete specific regions. All these processes require the ability to selectively hydrolyze phosphodiester bonds within the polynucleotide moleculeHydrolysis by acid or base cleave on the Bacteria and other microorganisms contain endonucleases that hydrolyze duplex DNA at specific internal sequences. The isolation of these enzymes provided one of the major breakthroughs that allowed the development of genetic engineering. For the first time, there was a method to "cut" DNA at specific locations, and to eventually combine DNA fragment in new and useful arrangements. These endonucleases are termed restriction endonucleases, and are actually part of a microorganisms immune system to protect against invasion by foreign DNA.Type I, II and III restriction endonucleasesType I:
Phosphodiester Linkage - Biology As Poetry
In phosphodiester formation, two (OH) groups on the phosphate molecule bind to the 3’ and 5’ carbons on two independent pentose sugars. These are two condensation reactions, so two molecules of water are produced. The phosphate is then bonded to the sugars by two ester bonds, hence the nomenclature of phosphodiester bond. This reaction is catalysed by , such as during .
Phosphodiester Hydrolysis by Lanthanide Complexes of …
The largest efficiency of catalysis is observed for a phosphodiester lacking the intramolecular hydroxyl group, and the smallest efficiency is observed for a phosphotriester.