0
How does bacterial cell protect its own DNA from restriction enzymes?
Wiki User
∙ 9y ago
In order to protect the bacterial genomic DNA from its own restriction enzymes, bacterial cells employ a system, wherein methyl transferases methylate certain bases on the DNA sequence, making them unrecognizable to the restriction enzymes.
Each restriction enzyme has a methylase associated with it on the chromosome. This methylase puts methyl groups on the host DNA, and the restriction enzyme doesn't recognize its recognition sequence when it is so methlyated. The host DNA is thus protected from the actions of its own restriction enzyme.
Incoming (foreign) DNA is unlikely to be protected (methylated) in the same manner, thus this invading DNA is digested by the hosts restriction enzyme(s).
When working in cloning experiments, the principle is the same -- DNA to be digested is carried by a plasmid in a host that does not methylate DNA in the pattern that would cause the restriction enzyme to see it as protected, thus it is cut. DNA generated by PCR is similarly unmethylated, and is therefore also digested.
Some enzymes won't cut DNA isolated from dam+ or dcm+ hosts (two common bacterial methylases), thus one must know the genotype of the host cloning strain if using a restriction enzyme whose action is blocked by dam ordcmmethylation.
Wiki User
∙ 9y ago
Add your answer:
Earn +20 pts
What do palindrome have to do with the way restriction enzymes cut DNA?
protect the bacterial cell
Why don't bacterial chromosomes get cut out with the restriction enzymes present in the cell?
Methyl groups are attached to all bacterial genetic material to protect it from its own restriction enzymes.
What does restriction endonuclease do?
They cut DNA at specific sequences. Restriction endonucleases work by cutting DNA at specific sequences. The places that are cut are known as restriction sites.
Function of restriction enzymes?
They cut strands of DNA at specific sites.
Large numbers of bacterial cells are not found in crown galls because?
cell walls protect the plant from bacterial invasion
What do palindrome have to do with the way restriction enzymes cut DNA?
protect the bacterial cell
Why don't bacterial chromosomes get cut out with the restriction enzymes present in the cell?
Methyl groups are attached to all bacterial genetic material to protect it from its own restriction enzymes.
What is the enzyme function of restriction enzymes?
We believe the function of the restriction enzyme is to protect an organism from foreign DNA as restriction enzymes cleave DNA strands (making them useless). The idea is that bacteria use this to protect against viral infection as viruses attach to the cell and insert their DNA into it in order to "take over" the cell. Restriction enzymes recognize this DNA as foreign and begin to chop it up, saving the cell.
Where restriction enzymes come from?
Restriction enzyme, also called restriction endonuclease, a protein produced by bacteria that cleaves DNA at specific sites along the molecule. In the bacterial cell, restriction enzymes cleave foreign DNA, thus eliminating infecting organisms.
What does restriction endonuclease do?
They cut DNA at specific sequences. Restriction endonucleases work by cutting DNA at specific sequences. The places that are cut are known as restriction sites.
Whatn functions do restriction enzymes have in living cells?
In the living bacterial cell, these enzymes destroy the DNA of certain invading viruses (bacteriophages), thus placing a "restriction" on the number of viral strains that can cause infection; the bacterium's own DNA is protected from cleavage by methyl (-CH3) groups, which are added by enzymes at the recognition sites to mask them.
Can virus get a bacteria?
Yes- Bacterial viruses are called bacteriophages. Some examples are T4 and T7 phages. They are complex DNA viruses that attach themselves to the cell surface and then inject their DNA to the inside of the bacteria. Bacteria have enzymes called restriction enzymes that cleave DNA at specific sites called restriction sites. These enzymes are the bacterium's defense against phages.
Function of restriction enzymes?
They cut strands of DNA at specific sites.
A certain bacterial colony originated from the division of a single bacterial cell Each cell in this colony will most likely?
synthesize the same proteins and enzymes
Why do bacteria naturally contain restriction enzymes?
Restriction enzymes are the bacteria's form of an 'immune system' against viruses (which can infect bacteria). When viruses try to insert their own DNA into a bacteria's genome, the restriction enzymes detect this foreign DNA and cut it out so that the viruses can't replicate and kill the cell.
Why restriction enzyme cannot cut its own DNA?
Restriction enzymes are produced by bacteria to help destroy foreign, invading DNA, such as the DNA of bacteriophage (a virus that infects bacterial cells). Every restriction enzyme comes with a methylase enzyme, or more specifically, a DNA methyltransferase. The methylase enzyme methylates (adds a methyl group) to the restriction endonuclease site on the cell's own DNA, which protects the sites from the restriction enzyme so that it does not degrade its own DNA.
What is the function of restriction enzymes that naturally occur in bacteria cells?
Restiriction enzymes, or endonucleases, splice (cut) apart two different sites of the nucleotide sequence on foreign DNA resulting in two different pieces of DNA for a gene of interest to be inserted. This usually occurs in bacteria such as E. coli and such. Once the two cuts have been made (one at 5' and one at 3') there remains the open ends of the DNA called 'sticky ends'. THis is where the gene of interest is inserted.
