FACTOID # 30: If Alaska were its own country, it would be the 26th largest in total area, slightly larger than Iran.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > DNase

A deoxyribonuclease (DNase, for short) is any enzyme that catalyzes the hydrolytic cleavage of phosphodiester linkages in the DNA backbone. Deoxyribonucleases are thus one type of nuclease. A wide variety of deoxyribonucleases are known, which differ in their substrate specificities, chemical mechanisms, and biological functions. Neuraminidase ribbon diagram An enzyme (in Greek en = in and zyme = blend) is a protein, or protein complex, that catalyzes a chemical reaction and also controls the 3D orientation of the catalyzed substrates. ... Hydrolysis is a chemical process in which a molecule is cleaved into two parts by the addition of a molecule of water. ... Diagram of phosphodiester bonds between nucleotides A phosphodiester bond is a group of strong covalent bonds between the phosphorus atom in a phosphate group and two other molecules over two ester bonds. ... DNA replication Deoxyribonucleic acid (DNA) is a nucleic acid which is capable of carrying genetic instructions for the biological development of all cellular forms of life and many viruses. ... A nuclease is an enzyme capable of cleaving the phosphodiester bonds between the nucleotide subunits of nucleic acids. ... In biochemistry, a substrate is a molecule which is acted upon by an enzyme. ...


Some DNases cleave only residues at the ends of DNA molecules (exodeoxyribonucleases, a type of exonuclease). Others cleave anywhere along the chain (endodeoxyribonucleases, a subset of endonucleases). Some are fairly indiscriminate about the DNA sequence at which they cut, while others, including restriction enzymes, are very sequence-specific. Some cleave only double-stranded DNA, others are specific for single-stranded molecules, and still others are active toward both. A DNA sequence (sometimes genetic sequence) is a succession of letters representing the primary structure of a real or hypothetical DNA molecule or strand, The possible letters are A, C, G, and T, representing the four nucleotide subunits of a DNA strand (adenine, cytosine, guanine, thymine), and typically these are... A restriction enzyme (or restriction endonuclease) is an enzyme that cuts double-stranded DNA. The enzyme makes two incisions, one through each of the phosphate backbones of the double helix without damaging the bases. ...


Deoxyribonuclease I cleaves DNA preferentially at phosphodiester linkages adjacent to a pyrimidine nucleotide, yielding 5'-phosphate terminated polynucleotides with a free hydroxyl group on position 3', on average producing tetranucleotides. It acts on single-stranded DNA, double-stranded DNA, and chromatin.


Deoxyribonuclease II, or Acid DNase, hydrolyzes deoxyribonucleotide linkages in native and denatured DNA yielding products with 3'-phosphates. As the name implies, it is more effective at acid pHs.


  Results from FactBites:
 
DNase I Acutely Increases Cystic Fibrosis Sputum Elastase Activity and its Potential to Induce Lung Hemorrhage in Mice ... (3348 words)
DNase I Acutely Increases Cystic Fibrosis Sputum Elastase Activity and its Potential to Induce Lung Hemorrhage in Mice
The effect of different DNase I concentrations on sputum elastase activity is shown in Figure 2.
In summary, the DNase I-mediated increase in CF sputum elastase activity is associated with an increase in the potential of
Ambion's Tips From the Bench: DNase I Demystified (1459 words)
The smallest substrate for DNase I is a trinucleotide.
Although DNase I is commonly perceived to cleave DNA nonspecifically, in practice it does show some sequence preference.
While DNase I can be removed by phenol extraction, many researchers avoid this method for fear of loss of precious RNA sample during the extraction, and because it is time consuming and requires handling phenol, a hazardous chemical.
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m