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Is topoisomerases belong to restriction enzymes?
Restriction enzymes (also known as restriction endonucleases) are proteins which cut DNA up at specific sequences in the genome. For example, the commonly used restriction end…onuclease EcoRI recognizes every point in DNA with the sequence GAATTC, and cuts at the point between the Guanine and Adenine. Interestingly, the recognition sequences for most restriction endonucleases are genetic palindromes, e.g., the sequence reads exactly the same backwards on the complementary strand. In the case of EcoRI, the two complementary DNA strands for the recognition sequence are: 5'--GAATTC ---3' 3'--CTTAAG--5'
A restriction enzyme (also known as restriction endonuclease) is protein which cuts DNA up at specific sequences (called restriction sites) in a genome. For example, the commo…nly used restriction endonuclease EcoRI recognizes every DNA sequence GAATTC and cuts at the point between the guanine and the adenine in that sequence, forming blunt ends (or straight, even ends). Interestingly and coincidentially, the restriction site for most restriction enzymes are genetic palindromes (the sequence reads exactly the same backwards on the complementary strand). In the case of EcoRI, the two complementary DNA strands for the restriction site are: 5'-- GAATTC --3' 3'-- CTTAAG --5' After this DNA sequence is cut, it might look something like this: 5'-- G AATTC --3' 3'-- C TTAAG --5'
Restriction enzyme cuts double or single stranded DNA at a specific recognition nucleotide sequences known as restriction site.
restriction enzymes cut the DNA at specific sites called restriction sites. These restriction sites are 6 - 8 base pairs long and occur at different frequencies on the DNA
Restriction enzymes are obtained from many prokaryotes and about 1500 enzymes with known sequence recognition sites have been isolated. Restriction enzyme is a protein tha…t recognize a specific, short nucelotide sequence.
Topoisomerase: are isomerase enzymes that act on the topology of DNA Helicase untwists the double helix and separates the template DNA strands at the replication f…ork. This untwisting causes tighter twisting ahead of the replication fork, and topoisomerase helps relieve this strain
The function of topoisomerase is to unwind the helix of DNA into a regular, ladder-like shape. Topoisomerase is only found in primates. In other organisms, the molecule is cal…led gyrase that unwinds the DNA.
Viruses produce restriction enzymes
Bacterias use restriction enzymes as a form of defense mechanism. We as people use these restriction enzymes in bacterias to aid us in genetic engineering.
There are actually two types of restriction enzymes, type I and type II. The form commonly referred to as 'restriction enzyme' are type II. These enzymes recognize specific se…quences in the DNA and will cut at the sequence, and only that sequence. Within in the type II restriction enzymes there are two types, those which leave an overhang and those which leave a blunt end. An example of a restriction enzyme is BglII, which will cut the sequence AGATCT between the first A and the second G. This is an example of a enzyme which produces a overhang; remember DNA is double stranded, and on the converse strand the sequence is TCTAGA. BglII will cut this strand between the fifth G and the sixth A. So why doesn't restriction enzymes cut the DNA in the organisms where they are found? Well it turns out, the organisms protect their own DNA by adding methyl groups to the sequence where the restriction enzyme will cut. This restriction enzymes serve as a primitive immune system, any DNA which enters the cell (a virus for instance) will not be methylated, and hopefully the restriction enzymes can chop up the foreign DNA before it can cause any damage.
There main purpose is to cut up viral DNA that invades bacteria. Since they do this at definite sites, depending on which restriction enzyme is used, they can be used in genet…ic recombination exercises. Inserting sections of DNA into bacterial plasmids so that desired products will be made by these bacteria.
TaqI's restriction site is: TCGA AGCT
Restriction enzyme in bacteria cuts of the foreign DNA inside the host, thus destroying them. The host DNA is protected against this destructive action due to methylation of t…he host DNA.
Restriction enzymes come from bacteria found in DNA
Enzymes are proteins so they are made in the ribosomes. They are synthesized from amino acids that are coded for in the DNA.