9.1 Sequence-specific DNAfragmentationRestrictionenzymes:Endonucleases made bybacteria that recognize specificshort nucleotide seguences andcutDNA at those sites9-6
9-6 Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display Restriction enzymes: Endonucleases made by bacteria that recognize specific, short nucleotide sequences and cut DNA at those sites. 9.1 Sequence 9.1 Sequence-specific DNA fragmentation specific DNA fragmentation
TABLE9.1TenCommonlyUsedRestrictionEnzymesSequenceofMicrobial OriginEnzymeRecognition Site4-8 base pairsTaqlThermusaquaticusYi198Palindromic symmetryCut both DNA strands atRsalRhodopseudomonassphaeroidesidentical base sequenceSau3AlStaphylococcusaureus3AECORIEscherichia coliBamHiBacillusamyloliquefaciensH.HindillHaemophilusinfluenzaeKpntKlebsielia pneumoniaeOK8ClalCaryophanon latumBacillusBssHII999999stearothermophilusGdadNotiNocardiaotitidiscaviarumodooacoccooaad
9-7 Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display 4-8 base pairs Palindromic symmetry Cut both DNA strands at identical base sequence
Restriction enzymes cut DNA molecules at specificlocations and produce either blunt or sticky endsa)Bluntends(Rsal)Sugar-phosphateRsalbackbone5AAASHASSSb)Sticky5ends(EcoRl)ECORI5-5overhangsc)Sticky3'ends(Kpnl)3'overhangsKpr2-TAAT59-8Fig.9.2
9-8 Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display Restriction enzymes cut DNA molecules at specific Restriction enzymes cut DNA molecules at specific locations and produce either blunt or sticky ends locations and produce either blunt or sticky ends Fig. 9.2
Restriction fragments:TheDNAfragmentsB-BamRrPlasmidE:EcoRrocahyrexgenerated by restrictionCenzymes.BamHLDigestion: The cutting ofDNA by restrictionEcoRtBulEEE1aenzymes.Lineanfnagmanty9-9
9-9 Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display Restriction fragments: The DNA fragments generated by restriction enzymes. Digestion: The cutting of DNA by restriction enzymes
Restriction enzymes are bacterial weaponsagainstbacteriophageattack1.Phage attachesProteincoattobacterium(host).DNACell bursts,清releasingnew限phage.39福Core2.PhageinjectsHostcell wallits genes intohostcellT2phageP4.Phageparticles3.PhageDNAreplicates:assemble.newphageproteinsaremadeFig.6.69-10
9-10 Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display Restriction enzymes are bacterial weapons Restriction enzymes are bacterial weapons against against bacteriophage bacteriophage attack Fig. 6.6