PlasmidInfo:
PlasmidInformation
ProductName:pSF-T7-LacO-BetaGal
ProductCode:OG4202
Size(bp):8514bp
BacterialAntibioticSelection:KanR
OriginandCompatibility:pUChighcopyderivedfrompBR322
BacterialCopyNumber:500-700percell
Promoter:
PlasmidPurpose:
ThisplasmidisdesignedtoexpresstaggedproteinsinE.coli.ItcontainstheT7promoterthatcanberegulatedusingtheLacrepressor.ThisallowsforgreatercontroloverexpressionincomparisontonormalT7promoterplasmids.InordertousethisplasmidyouwillrequireaT7polymeraseexpressingE.colicelllinethatalsoexpressestheLacIrepressor.AcommonexpressioncelllinethatcanbeusedforthispurposeistheBL21(DE3)strain.
PromoterExpressionLevel:ThisplasmidcontainstheIPTGinducIBLepromoterthatwascreatedbythefusionoftheLacpromoterandtheTryptophanoperonpromoter.ItallowsinducibleexpressioninE.coliusingIPTGastheinducingagent.
SequenceandMap:
OtherInfo:
TranscriptionTermination:ThisplasmidcontainsthreealternativetranscriptionterminatorsforTagT7LacOInduciblebacterialandbacteriophage(T7)expression.Thismeansthatonlythepromoterneedstobechangedtoaltertheexpressionsystemyouareusing.Wesellmultiplepromotersthatcanbeusedineachofthesesystems.Thepresenceofeachterminatordoesnotreduceexpressioninthealternativesystems.
Cloning:
CloninginaGene:Thisplasmidhasbeendesignedtobecompatiblewitharangeofcloningtechniques.Themultiplecloningsitecontainsarangeofstandardcommonlyusedrestrictionsitesforcloning.UsingthesesitesgenescanbeinsertedusingstandardcloningmethodswithDNAligase.Othermethodssuchasligaseindependentcloning(LIC)GibsonAssemblyInFusionHDorSeamlessGeneArtcanalsobeusedandbecauseallofourplasmidsarebasedonthesamebackbonethesamemethodcanbeusedforcloningintoallofourcataloguevectors.
Multiplecloningsitenotes:ThereareafewimportantsiteswithintheMCS.TheseincludetheNcoIsitetheXbaIsiteandtheBsgIandBseRIsites.TheNcoIsitecontainsastartcodonthatisimmediatelydownstreamofbothaKozakandShine-Dalgarnoribosomalbindingsite.Theseallowforoptimalpositioningofgeneswhenthestartcodonisplacedinthislocation.IfthisisnotrequiredandyouwishtouseadownstreamsiteforgenecloningyoucanremovetheNcoIsitebycleavingtheplasmidwithKpnI.
TheXbaIsitecontainsastopcodon.ThisstopcodonispositionedinaspecificpositioninrelationtotheBsgIandBseRIsitesthatareimmediatelydownstream.WheneitherBseRIorBsgIcleavetheplasmidtheyproduceaTAoverhangfromthestopcodonintheXbaIsitethatiscompatiblewithallofourpeptidetagplasmidscutwiththesamesites.BseRIandBsgIsitesarenon-palindromicandcleaveadefinednumberofbasesawayfromtheirbindingsite.
WheneverwecloneageneintoourmultiplecloningsitewealwayspositionthestartandstopcodoninthesamepositionsintheMCS.IfthestartandendsofthegenesarenotcompatiblewithNcoIandXbaIweextendthesequencetothenearestexternalsitesbutkeepthestartandstopcodonslocationsconsistent.
1:SnapFusionCloning:IfyouwouldliketofuseyourcodingsequencetothetagwithminimaladditionalbasesyoucanuseourSnapFusiontechnology.ThisprocessinvolvesamplifyingyourgenebyPCRtoaddspecificrestrictionsitesontotheends.WhenthesesitesarecuttheyproduceanoverhangthatiscompatiblewiththisplasmidcutwithBseRIorBsgI.
Toinsertyourgene:
1:Amplifyyourgenewithprimersdesignedusingthisspreadsheet
2:CuttheplasmidwitheitherBseRIorBsgI.*
3:Cutyourgenewiththeenzymeyouaddedusingthespreadsheet(anyofAcuIBpmIBpuEIBseRIBsgIEciI).
4:ClonethegeneintotheplasmidusingDNAligase.
UsingthismethodwithanN-terminaltagplasmidwillresultinthetagcodingsequenceimmediatelyfollowedbyyourgenesATGstartcodonatthejoin.Thisresultsinaseamlessfusionofthetwosequenceswithnoextrabasesbeingadded.UsingthismethodonC-terminaltagplasmidswillconvertyourgenesstopcodonintoaTAC(TyrY)codonfollowedbytheplasmidtagcodingsequence.Thisresultsinnoextrabasesbetweenyourgeneandthetag.Seethediagrambelowformoreinformation.
*PleasenotethatinsectexpressionplasmidscannotbecutwithBsgIonlyBseRIbecauseofunavoidableconflictingsitesinthebackbone.AlsoYeastplasmidscannotbecutwithBseRIbecauseofunavoidablerestrictionsitesinthebackbone.
Usingthistechniquewillcreateagenefragmentthatcanbeligatedintoanyorour>1500peptideandreportertagplasmids.Ifyouuseoneoftheothertechniquesbelow(GibsonInFusionSeamlessorLIC)youwillneednewprimersforeveryvectoryoucloneintobecausethearmsofhomologywillchangeaccordingtothetagplasmidyouarecloninginto.
Ifyoufindthatyourgenesequencehassitesinitthatmakeusingthiscloningstrategydifficultyoucanstilluseoneofthealternativemethodsbelow(e.g.standardcloningorGibsoncloning).
OpenthePrimerDesignTooltohelpyoudesignprimersforcloningyourgeneinourSnapFusiontechnique.
2:StandardEnzymes:Ifyouarenotconcernedaboutleavingafewextrabasesbetweenthetagcodingsequenceandyourgeneyoucancloneyourgeneintothevectorusingstandardcloningrestrictionenzymes.Thisstrategywillrequireyoutochoosewhichenzymesyouwanttousetocloneyourgene.
OpenthePrimerDesignToolwhichprovidesprimerswithdifferentenzymechoicespositioningyourgeneasclosetothetagaspossibleineachcase.Pleasenotethatstandardenzymeswillalwaysleaveadditionalnucleotidesbetweenyourgeneandthetagbutusingthespreadsheetwillensurethetagandgeneareinframe.
3:Gibsoncloning/InfusionHD/GeneArtSeamless/LigaseIndependentCloning(LIC)Methods:ThesecloningtechniquesusereagentssoldbyothercompaniesandallowyoutofusesequencestogetherusingenzymesthatchewbacktheDNAtoleaveoverlappingends/overhangs.ThesubsequentmethodofjoiningtheDNAdependsonthekitused.Touseoneofthesetechniquesyoucaneitherdesignyourownprimersoryoucanusethespreadsheetbelowtohelpwiththedesign.
OpenthePrimerDesignTooltohelpyoudesignprimersforcloningyourgeneusingGibsonassemblyInfusionHDGeneArtSeamlesscloningorLigaseIndependentCloning(LIC)techniques.
IPStatus:
IntellectualPropertyStatusThisproductispartofourSnapFastplasmidrange,formoreinformationontheIntellectualpropertystatusofthisplasmidpleaseclickhere
