Search results
Results from the WOW.Com Content Network
The restriction modification system (RM system) is found in bacteria and archaea, and provides a defense against foreign DNA, such as that borne by bacteriophages.. Bacteria have restriction enzymes, also called restriction endonucleases, which cleave double-stranded DNA at specific points into fragments, which are then degraded further by other endonucleases.
DNA adenine methylase, (Dam) [1] (also site-specific DNA-methyltransferase (adenine-specific), EC 2.1.1.72, modification methylase, restriction-modification system) is an enzyme that adds a methyl group to the adenine of the sequence 5'-GATC-3' in newly synthesized DNA.
[4] [5] Inside a prokaryote, the restriction enzymes selectively cut up foreign DNA in a process called restriction digestion; meanwhile, host DNA is protected by a modification enzyme (a methyltransferase) that modifies the prokaryotic DNA and blocks cleavage. Together, these two processes form the restriction modification system. [6]
A restriction enzyme or restriction endonuclease is a special type of biological macromolecule that functions as part of the "immune system" in bacteria.One special kind of restriction enzymes is the class of "homing endonucleases", these being present in all three domains of life, although their function seems to be very different from one domain to another.
The type I restriction and modification system is composed of three polypeptides R, M and S. The M (hsdM) and S subunits together form a methyltransferase that methylates two adenine residues in complementary strands of a bipartite DNA recognition sequence .
Type III site-specific deoxyribonuclease (EC 3.1.21.5, type III restriction enzyme, restriction-modification system) is an enzyme. [1] This enzyme catalyses the following chemical reaction. Endonucleolytic cleavage of DNA to give specific double-stranded fragments with terminal 5'-phosphates
Restriction endonuclease (REase) EcoRII (pronounced "eco R two") is an enzyme of restriction modification system (RM) naturally found in Escherichia coli, a Gram-negative bacteria. Its molecular mass is 45.2 kDa, being composed of 402 amino acids. [1]
(Further reading: see the section "Nomenclature" in the article "Restriction enzyme".) PDB code: Code used to identify the structure of a protein in the PDB database of protein structures. The 3D atomic structure of a protein provides highly valuable information to understand the intimate details of its mechanism of action [3] [4].