Sticky end

As the second educt (B), the plasmid ONA with complementary sticky ends is prepared separately. In the first step the isolated plasmid DNA is cut open by a special type of enzyme called restriction endonuclease. It scans along the thread of DNA and recognizes short nucleotide sequences, e.g., CTGCAG, which ate cleaved at a specific site, e.g., between A and G. Some 50 of such enzymes are known and many are commercially available. The ends are then again extended witfa he aid of a terminal transferase by a short sequence of identical nucleotides complementary to the sticky ends of educt (A). 

The synthetic and plasmid DNAs are mixed and join their sticky ends spontaneously. They are covalently bound together by DNA ligases, when the resulting hybrid plasmid is inserted into bacterial cells. Dilute calcium chloride solutions render the bacterial membranes permeable and allow the passage of ONA into the cells. 

Fig. 3. Constmetion of a recombinant DNA by joining vector and passenger fragments where (I I I I I I) represent sticky ends. Both A and B genes represent selectable traits, so that introduction of foreign DNA in B gene leads to the loss of an identifiable function. REP represents repHcation and...

Therefore, DNA restriction fragments having such sticky ends can be joined together to create new combinations of DNA sequence. If the fragments are derived from DNA molecules of different origin, novel recombinant forms of DNA are created. 

Cleavage occurs at the G residue on each strand so that the DNA is cut in a staggered fashion, leaving 5 -overhanging single-stranded ends (sticky ends) ... 

Formation of DNA Periodic Arrays Based on Branched Motifs Heid Together by Sticky Ends... 

A somewhat similar approach has been nsed for the formation of nanosize wires stretching between gold electrodes [34]. Lambda-DNA was positioned between two electrodes, with immobilized oligonncleotides complementary to lambda-DNA sticky ends. Silver (Ag ) ions were deposited on the stretched DNA bridges, followed by rednction of absorbed ions to metallic silver with hydroquinone. The resulting silver clusters formed on DNA strands were found to be 100 nm in diameter and were capable of condncting the electric current. 

DNA is ideally suited as a structural material in supramolecular chemistry. It has sticky ends and simple rules of assembly, arbitrary sequences can be obtained, and there is a profusion of enzymes for modification. The molecule is stiff and stable and encodes information. Chapter 10 surveys its varied applications in nanobiotechnology. The emphasis of Chapter 11 is on DNA nanoensembles, condensed by polymer interactions and electrostatic forces for gene transfer. Chapter 12 focuses on proteins as building blocks for nanostructures. 

DNA polymerase 1 j Synthesizes double-stranded DNA from j single-stranded DNA. Synthesis of double-stranded cDNA nick translation generation of blunt ends from sticky ends. 

Piece of human DNA cut with same restriction nuclease and containing same sticky ends... 

Sticky-ends Complementary single-stranded tails projecting from otherwise double-helical nucleic acid molecules. 

Sense 5 T-(GN18)-TTCAAGAGA-(81NC)-TTTTTTC Antisense 5 TCGAGAAAAAA (GN18)-TCTCTTGAA-(81NC)-A Xhol sticky end... 

This activity is intended to be performed in conjunction with Experiment 66. Restriction endonucleases, or restriction enzymes, cleave DNA at specific base sequences, fragmenting the DNA into smaller pieces. The two strands of a DNA double helix are cleaved at different places, resulting in uneven fragments called sticky ends. Cleavage of DNA by restriction enzymes is a required first step in various types of DNA analysis, including DNA fingerprinting and recombinant DNA technology. 

A sticky end is an extension of nucleotides on one strand only of a dsDNA molecule. 

End filling is a more gentle method but can only be used on DNA molecules that have sticky ends. It uses the Klenow fragment, which fills in the sticky ends by synthesizing the complementary strand. Again if the reaction is carried out in the presence of labelled deoxynucleotides the result is a strand of DNA which is radioactively labelled. 

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