Where is DNase

[joveryant]

hi everyone, I have a littile question:

Since DNase degrades DNA into ATP......

We won't place DNA in RT for too long.

What confused me is "where is DNase come from?!"

[keef]

DNase as the name suggests, is an enzyme. the enzyme is manufactured by ribosomes in which it can after tat undergo post translational modifications or cotranslational modifications.

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.

[Dr.Stein]

Since DNase degrades DNA into ATP......

I don't think DNAse converts DNA into ATP... it is an enzyme to "open" the double-helix to facilitate transcription process This is not my major, I am blank

[joveryant]

Hi Keef! thank you

[dipjyoti]

DNase I is a versatile enzyme that nonspecifically cleaves DNA to release 5'-phosphorylated di-, tri-, and oligonucleotide products (1). A powerful research tool for DNA manipulations, DNase I is used in a range of molecular biology applications. Some of its uses include:

degradation of contaminating DNA after RNA isolation,
"clean-up" of RNA prior to RT-PCR and after in vitro transcription,
identification of protein binding sequences on DNA (DNase I footprinting),
prevention of clumping when handling cultured cells, and
creation of a fragmented library of DNA sequences for in vitro recombination reactions.
While frequently used in the laboratory, the activity of DNase I is still a mystery to many researchers. Are the "units" of one source of DNase I the same as that of another? Are calcium and magnesium ions required for activity? Will DNase I degrade DNA in DNA:RNA hybrids? Can DNase I remove 100% of DNA contamination from RNA preparations? In this article we will try to answer some of the questions surrounding this commonly used enzyme.

Better Unit Definition

The specific activity of a given DNase I preparation reflects the potency of the enzyme per unit mass in degrading double-stranded DNA (dsDNA). Historically, this activity has been expressed in Kunitz units (2), where 1 Kunitz unit is the amount of DNase I added to 1 mg/ml salmon sperm DNA that causes an increase of 0.001 absorbance units per min when assayed in a 0.1 M NaOAc (pH 5.0) buffer. This buffer, however, is not representative of the conditions that are typical for DNase I digestions (see "Treating RNA Samples with DNase I" at right). Consequently, Ambion offers DNase I with a unit designation that better reflects how well the enzyme will degrade DNA under standard conditions. Updated procedures measure DNase I activity using real-time fluorescence assays which allows for fast, quantitative measurements.

For further info see http://www.sigmaaldrich.com/Area_of_Int ... ase_I.html

Thanx!
Dip Jyoti Chakraborty