- Phosphodiester bond
A phosphodiester bond is a group of strong covalent bonds between the phosphorus atom in a
phosphate groupand two other molecules over two esterbonds. Phosphodiester bonds are central to all life on Earth, as they make up the backbone of the strands of DNA. In DNA and RNA, the phosphodiester bond is the linkage between the 3' carbon atomand the 5' carbon of the sugar deoxyribose(in DNA) or ribose(in RNA).
The phosphate groups in the phosphodiester bond are negatively-charged. Because the phosphate groups have a pKa near 0, they are negatively-charged at pH 7. This repulsion forces the phosphates to take opposite sides of the DNA strands and is neutralized by proteins (
histones), metal ions such as magnesium, and polyamines.
In order for the phosphodiester bond to be formed and the
nucleotides to be joined, the tri-phosphate or di-phosphate forms of the nucleotide building blocks are broken apart to give off energy required to drive the enzyme-catalyzed reaction. When a single phosphate or two phosphates known as pyrophosphates break away and catalyze the reaction, the phosphodiester bond is formed.
Hydrolysis of phosphodiester bonds can be catalyzed by the action of
phosphodiesterases which play an important role in repairing DNA sequences.
In biological systems, the phosphodiester bond between two
ribonucleotides can be broken by alkaline hydrolysisbecause of the free 2' hydroxyl group.
An enzyme that plays an important role in the repair of oxidative DNA damage is the 3'-phosphodiesterase.
During the replication of DNA, there is a hole between the phosphates in the backbone left by
DNA polymerase I. DNA ligaseis able to form a phosphodiester bond between the nucleotides.
DNA replication, DNA, ATP
Teichoic acid, DNase I
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Look at other dictionaries:
phosphodiester bond — n a covalent bond in RNA or DNA that holds a polynucleotide chain together by joining a phosphate group at position 5 in the pentose sugar of one nucleotide to the hydroxyl group at position 3 in the pentose sugar of the next nucleotide called… … Medical dictionary
phosphodiester bond — phospho diester bond A bond in which a phosphate group joins adjacent carbons through ester linkages. A condensation reaction between adjacent nucleotides results in a phosphodiester bond between 3 and 5 carbons in DNA and RNA … Glossary of Biotechnology
phosphodiester bond — fosfodiesterinis ryšys statusas T sritis chemija apibrėžtis Nukleorūgščių pagrindinis ryšys, susidarantis per fosfato rūgštį tarp dviejų ribozių 3′ ir 5′ hidroksigrupių. formulė (–O)₂P(=O)OH atitikmenys: angl. phosphodiester bond rus.… … Chemijos terminų aiškinamasis žodynas
phosphodiester bond — ¦fäs(ˌ)fōˌ… noun or phosphodiester linkage : a covalent bond in RNA or DNA that holds a polynucleotide chain together by joining a phosphate group at position 5 in the pentose sugar of one nucleotide to the hydroxyl group at position 3 in the… … Useful english dictionary
phosphodiester bond — Not a precise term. Refers to any molecule in which two parts are joined through a phosphate group. Examples are found in RNA, DNA, phospholipids, cyclic nucleotides, nucleotide diphosphates and triphosphates … Dictionary of molecular biology
phosphodiester — A diesterified orthophosphoric acid, RO–(PO2H)–OR′, as in the nucleic acid s. p. hydrolases SYN: phosphodiesterases. * * * phos·pho·di·es·ter dī es tər n an oligonucleotide with an oxygen atom linking consecutive nucleotides see … Medical dictionary
phosphodiester linkage — noun see phosphodiester bond … Useful english dictionary
phospho-diester bond — phosphodiester bond A bond in which a phosphate group joins adjacent carbons through ester linkages. A condensation reaction between adjacent nucleotides results in a phosphodiester bond between 3 and 5 carbons in DNA and RNA … Glossary of Biotechnology
nucleic acid — /nooh klee ik, klay , nyooh /, Biochem. any of a group of long, linear macromolecules, either DNA or various types of RNA, that carry genetic information directing all cellular functions: composed of linked nucleotides. [1890 95; NUCLE(US) + IC;… … Universalium
Hammerhead ribozyme — Taxobox | color=white name = Hammerhead Ribozyme image caption = Stylized rendering of the full length hammerhead ribozyme RNA molecule species = Catalytic RNAHammerhead RNAs are small self cleaving RNAs that have a conserved motif found in… … Wikipedia