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A restriction enzyme (or restriction endonuclease) is an enzyme that cuts double-stranded DNA. The enzyme makes two incisions, one through each of the sugar-phosphate backbones (i.e., each strand) of the double helix without damaging the nitrogenous bases. The term restriction comes from the fact that these enzymes were discovered in E. coli strains that appeared to be restricting the infection by certain bacteriophages. Restriction enzymes therefore are believed to be a mechanism evolved by bacteria to resist viral attack and to help in the removal of viral sequences. They are part of what is called the restriction modification system. Image File history File links Broom_icon. ... Endonucleases are enzymes that cleave the phosphodiester bond within a nucleotide chain. ... Ribbon diagram of the enzyme TIM, surrounded by the space-filling model of the protein. ... The structure of part of a DNA double helix Deoxyribonucleic acid, or DNA, is a nucleic acid molecule that contains the genetic instructions used in the development and functioning of all known living organisms. ... A nucleotide is a chemical compound that consists of 3 portions: a heterocyclic base, a sugar, and one or more phosphate groups. ... See also Entamoeba coli. ... ... The restriction modification system is used by prokaryotic organisms (i. ...

The chemical bonds that the enzymes cleave can be reformed by other enzymes known as ligases, so that restriction fragments carved from different chromosomes or genes can be spliced together, provided their ends are complementary (more below). Many of the procedures of molecular biology and genetic engineering rely on restriction enzymes. A chemical bond is the physical process responsible for the attractive interactions between atoms and molecules, and that which confers stability to diatomic and polyatomic chemical compounds. ... It has been suggested that sticky end/blunt end be merged into this article or section. ... A scheme of a condensed (metaphase) chromosome. ... For other uses, see Gene (disambiguation). ... In genetics, splicing is a modification of genetic information after transcription, in which introns of precursor messenger RNA (pre-mRNA) are removed and exons of it are joined. ... Molecular biology is the study of biology at a molecular level. ... Kenyans examining insect-resistant transgenic Bt corn. ...

The 1978 Nobel Prize in Medicine was awarded to Daniel Nathans, Werner Arber and Hamilton Smith for the discovery of restriction endonucleases, leading to the development of recombinant DNA technology. The first practical use of their work was the manipulation of E. coli bacteria to produce human insulin for diabetics. The Nobel Prize (Swedish: ), as designated in Alfred Nobels will in 1895, is awarded in Physics, Chemistry, Physiology or Medicine, Literature, and Peace. ... Daniel Nathans (October 30, 1928 - November 16, 1999) was a U.S. microbiologist. ... Werner Arber (born June 3, 1929) is a Swiss microbiologist. ... Hamilton Smith (1931- ) is a Nobel prize winning geneticist. ... Recombinant DNA (rDNA) is an artificial DNA sequence resulting from the combination of different DNA sequences. ... See also Entamoeba coli. ... Not to be confused with inulin. ... This article is about the disease that features high blood sugar. ...

Fragment complementarity and splicing

EcoRI digestion produces "sticky" ends.

SmaI restriction enzyme cleavage produces "blunt" ends.

Because recognition sequences and cleavage sites differ between restriction enzymes, the length and the exact sequence of a sticky-end "overhang", as well as whether it is the 5' end or the 3' end strand that overhangs, depends on which enzyme produced it. Base-pairing between overhangs with complementary sequences enables two fragments to be joined or "spliced" by a DNA ligase. A sticky-end fragment can be ligated not only to the fragment from which it was originally cleaved, but also to any other fragment with a compatible sticky end.The sticky end is also called a cohesive end or complementary end in some reference. If a restriction enzyme has a non-degenerate palindromic cleavage site, all ends that it produces are compatible. Ends produced by different enzymes may also be compatible. Image File history File links EcoRI_restriction_enzyme_recognition_site. ... Image File history File links EcoRI_restriction_enzyme_recognition_site. ... Image File history File links SmaI_restriction_enzyme_recognition_site. ... Image File history File links SmaI_restriction_enzyme_recognition_site. ... In molecular biology, the 5 end and the 3 end (pronounced 5-prime and 3-prime) are respectively the leading and tail ends of a strand of nucleic acid. ... In molecular biology, the 5 end and the 3 end (pronounced 5-prime and 3-prime) are respectively the leading and tail ends of a strand of nucleic acid. ... Base pairs, of a DNA molecule. ... It has been suggested that sticky end/blunt end be merged into this article or section. ...

Restriction enzymes as tools

See the main article on restriction digests.

Recognition sequences typically are only four to twelve nucleotides long. Because there are only so many ways to arrange the four nucleotides--A,C,G and T--into a four or eight or twelve nucleotide sequence, recognition sequences tend to "crop up" by chance in any long sequence. Furthermore, restriction enzymes specific to hundreds of distinct sequences have been identified and synthesized for sale to laboratories. As a result, potential "restriction sites" appear in almost any gene or chromosome. Meanwhile, the sequences of some artificial plasmids include a "linker" that contains dozens of restriction enzyme recognition sequences within a very short segment of DNA. So no matter the context in which a gene naturally appears, there is probably a pair of restriction enzymes that can snip it out, and which will produce ends that enable the gene to be spliced into a "plasmid" (i.e. which will enable what molecular biologists call "cloning" of the gene). A restriction digest is a molecular biology procedure used to prepare DNA for analysis or other processing. ... For other uses, see Gene (disambiguation). ... A scheme of a condensed (metaphase) chromosome. ... Figure 1: Illustration of a bacterium with plasmids enclosed showing chromosomal DNA and plasmids. ... Figure 1: Illustration of a bacterium with plasmids enclosed showing chromosomal DNA and plasmids. ... For other uses, see clone. ...

Another use of restriction enzymes can be to find specific SNPs. If a restriction enzyme can be found such that it cuts only one possible allele of a section of DNA (that is, the alternate nucleotide of the SNP causes the restriction site to no longer exist within the section of DNA), this restriction enzyme can be used to genotype the sample without completely sequencing it. The sample is first run in a restriction digest to cut the DNA, then gel electrophoresis is performed on this digest. If the sample is homozygous for the common allele, the result will be two bands of DNA, because the cut will have occurred at the restriction site. If the sample is homozygous for the rarer allele, the sample will show only one band, because it will not have been cut. If the sample is heterozygous at that SNP, there will be three bands of DNA. This is an example of restriction mapping, see the article on restriction maps DNA strand 1 differs from DNA strand 2 at a single base-pair location (a C/T polymorphism). ... For the hard rock band, see Allele (band). ... Restriction sites, or restriction recognition sites, are particular sequences of nucleotides that are recognized by restriction enzymes as sites to cut the DNA molecule. ... This article does not cite any references or sources. ... A restriction digest is a molecular biology procedure used to prepare DNA for analysis or other processing. ... Gel electrophoresis is a technique used for the separation of deoxyribonucleic acid, ribonucleic acid, or protein molecules through an electric charge. ... Homozygote cells are diploid or polyploid and have the same alleles at a locus (position) on homologous chromosomes. ... Heterozygote cells are diploid or polyploid and have different alleles at a locus (position) on homologous chromosomes. ... Restriction Mapping In molecular biology, restriction maps are used to compare relatedness of two different species at the molecular level. ...

Many recognition sequences are palindromic

Restriction enzymes recognize a specific sequence of nucleotides and produce a double stranded cut in the DNA that prevents the phage from replicating. While recognition sequences vary widely, many of them are palindromic; that is, the sequence on one strand reads the same in the same direction on the complementary strand. The meaning of "palindromic" in this context is different from what one might expect from its linguistic usage: GTAATG is not a palindromic DNA sequence, but GTATAC is (GTATAC is complementary to CATATG). For the movie, see Palindromes (film). ...

Types of restriction enzymes: Type 1:It breaks DNA about 100 after the restricted length and it should use ATP(energy) Type 2:it breaks DNA in restricted length so it is the most useful one for restricting known base pairs especially for genetic engineering Type 3:it breaks DNA about20_30 base pairs after the restricted length and it should use ATP (energy) Restricted lengths are between 4 to 8 base pairs that the restriction enzyme knows them. Each restriction enzyme searches for the restricted length and its supplementary .restriction enzyme usually knows the palindrome base pairs because the restricted length and their supplementary are the same. And some cells like bacteria save their genes by modifying them by using methyl and make viruses genes useless by restricting them We can find the succession of DNA by restricting it and make overlapping clones and electrophoresesing them. in this system we can find some repeated parts from DNA and find order of them. Viruses use overlapping system to be sure that they have recombined all parts of their genes

Naming

Restriction enzymes are named based on the bacteria in which they are isolated in the following manner:

restriction enzymes:

Types of restriction enzymes: Type 1:It breaks DNA about 100 after the restricted length and it should use ATP(energy) Type 2:it breaks DNA in restricted length so it is the most useful one for restricting known base pairs especially for genetic engineering Type 3:it breaks DNA about20_30 base pairs after the restricted length and it should use ATP (energy) Restricted lengths are between 4 to 8 base pairs that the restriction enzyme knows them. Each restriction enzyme searches for the restricted length and its supplementary .restriction enzyme usually knows the palindrome base pairs because the restricted length and their supplementary are the same. And some cells like bacteria save their genes by modifying them by using methyl and make viruses genes useless by restricting them We can find the succession of DNA by restricting it and make overlapping clones and electrophoresesing them. in this system we can find some repeated parts from DNA and find order of them. Viruses use overlapping system to be sure that they have recombined all parts of their genes

Examples

 5'GAATTC 3'CTTAAG 

 5'---G AATTC---3' 3'---CTTAA G---5' 

 5'GGATCC 3'CCTAGG 

 5'---G GATCC---3' 3'---CCTAG G---5' 

 5'AAGCTT 3'TTCGAA 

 5'---A AGCTT---3' 3'---TTCGA A---5' 

 5'TCGA 3'AGCT 

 5'---T CGA---3' 3'---AGC T---5' 

 5'GCGGCCGC 3'CGCCGGCG 

 5'---GC GGCCGC---3' 3'---CGCCGG CG---5' 

 5'GANTC 3'CTNAG 

 5'---G ANTC---3' 3'---CTNA G---5' 

 5'GATC 3'CTAG 

 5'--- GATC---3' 3'---CTAG ---3' 

 5'CAGCTG 3'GTCGAC 

 5'---CAG CTG---3' 3'---GTC GAC---5' 

 5'CCCGGG 3'GGGCCC 

 5'---CCC GGG---3' 3'---GGG CCC---5' 

 5'GGCC 3'CCGG 

 5'---GG CC---3' 3'---CC GG---5' 

 5'AGCT 3'TCGA 

 5'---AG CT---3' 3'---TC GA---5' 

 5'GATATC 3'CTATAG 

 5'---GAT ATC---3' 3'---CTA TAG---5' 

 5'GGTACC 3'CCATGG 

 5'---GGTAC C---3' 3'---C CATGG---5' 

 5'CTGCAG 3'GACGTC 

 5'---CTGCA G---3' 3'---G ACGTC---5' 

 5'GAGCTC 3'CTCGAG 

 5'---GAGCT C---3' 3'---C TCGAG---5' 

 5'GTCGAC 3'CAGCTG 

 5'---G TCGAC---3' 3'---CAGCT G---5' 

 5'AGTACT 3'TCATGA 

 5'---AGT ACT---3' 3'---TCA TGA---5' 

 5'GCATGC 3'CGTACG 

 5'---G CATGC---3' 3'---CGTAC G---5' 

 5'TCTAGA 3'AGATCT 

 5'---T CTAGA---3' 3'---AGATC T---5' 

In molecular biology, EcoRI (pronounced Eco R One) is a commonly used restriction enzyme. ... E. coli redirects here. ... BamHI is a restriction enzyme, derived from bacillus amyloliquefaciens. ... Bacillus amyloliquefaciens is a species of bacteria that is the source of the BamH1 restriction site. ... HindIII is a nuclease isolated from Haemophilus influenzae. ... Binomial name Haemophilus influenzae (Lehmann & Neumann 1896) Winslow 1917 Haemophilus influenzae, formerly called Pfeiffers bacillus or Bacillus influenzae, is a non-motile Gram-negative coccobacillus first described in 1892 by Dr. Richard Pfeiffer during an influenza pandemic. ... A restriction enzyme (or restriction endonuclease) is an enzyme that cuts double-stranded DNA. The enzyme makes two incisions, one through each of the phosphate backbones of the double helix without damaging the bases. ... Binomial name Thermophilus aquaticus Brock & Freeze, 1969 Thermophilus aquaticus is a species of bacterium that can tolerate high temperatures; it is the source of the heat-resistant enzyme Taq DNA Polymerase, one of the most important enzymes in molecular biology because of its use in the polymerase chain reaction. ... Binomial name Haemophilus influenzae (Lehmann & Neumann 1896) Winslow 1917 Haemophilus influenzae, formerly called Pfeiffers bacillus or Bacillus influenzae, is a non-motile Gram-negative coccobacillus first described in 1892 by Dr. Richard Pfeiffer during an influenza pandemic. ... Binomial name Rosenbach 1884 Staphylococcus aureus , literally Golden Cluster Seed and also known as golden staph, is the most common cause of staph infections. ... Binomial name Hauser 1885 Proteus vulgaris is a rod-shaped (bacilli) Gram negative bacterium (a chemoheterotroph) that inhabits the intestinal tracts of animals and can be pathogenic. ... Binomial name Serratia marcescens Bizio 1823 Serratia marcescens is a Gram negative bacterium, a human pathogen of the family Enterobacteriaceae. ... The DNA nucleotide sequence coding for synthesis of HaeIII. HaeIII is one of the 100+ restriction enzymes (endonucleases) discovered since 1970. ... EcoRV crystal structure complexed with double-stranded DNA EcoRV (pronounced eco R five) is a nuclease enzyme isolated from certain strains of E. coli, In molecular biology, it is a commonly used restriction enzyme. ... E. coli redirects here. ... Binomial name Klebsiella pneumoniae (Schroeter 1886) Trevisan 1887 Klebsiella pneumoniae is a Gram-negative, nonmotile, encapsulated, lactose-fermenting, facultatively anaerobic, rod-shaped bacterium found in the normal flora of the mouth, skin, and intestines. ... Binomial name Streptomyces achromogenes Okami and Umezawa 1953 Streptomyces achromogenes is a species of gram-positive bacterium that belongs in the genus Streptomyces. ...

References

1. ^ ^{a b c d e f g} Molecular cell biology. Lodish, Harvey F. 5. ed. : - New York : W. H. Freeman and Co., 2003, 973 s. b ill. ISBN: 0-7167-4366-3

External links

• Restriction Enzyme Digestion of DNA Protocol
• Restriction enzymes: protein data bank molecule of the month
• REBASE - The Restriction Enzyme Database
• Restriction enzyme finder
• pDRAW32 - Freeware software for restriction analysis
• WatCut - An online tool for restriction analysis
• Restriction digest of DNA - Online tool, free source code (PHP)
• Restriction Homepage - Six different tools
• Restriction Endonucleases: Molecular Scissors for Specifically Cutting DNA - a review from the Science Creative Quarterly
• Type I Restriction-Modification Systems - Home Page
• MeSH DNA Restriction Enzymes