Oxford Genetics/pSF-T7-LacO-NH2-6His- STag-EKT (OG4401)/OG4401/1 Ea

PlasmidInfo:

PlasmidPurpose:

ThisplasmidisdesignedtoexpresstaggedproteinsinE.coli.ItcontainstheT7promoterthatcanberegulatedusingtheLacrepressor.ThisallowsforgreatercontroloverexpressionincomparisontonormalT7promoterplasmids.InordertousethisplasmidyouwillrequireaT7polymeraseexpressingE.colicelllinethatalsoexpressestheLacIrepressor.AcommonexpressioncelllinethatcanbeusedforthispurposeistheBL21(DE3)strain.

Thisplasmidalsoencodesaproteasecleavagesitethatisdesignedtobepositionedbetweenyourgeneofinterestandthetagtoallowtheremovalofthetagfollowingproteinpurificationorisolation.ThisplasmidcontainsaEKTcleavagetag.Theproteinsequenceofthecleavagetagis:DDDDK.Enterokinase(EKT)proteasecleavesaftertheLysineresidue.Itcancleaveatotherbasicresiduesbutthisisdependentonproteinconfirmation.Ifaprolinefollowsthesiteitwillnotcut.Noneofourproductscontainaprolineafterthesite.

Formoreinformationonwhichcleavagetagtouseseeourcleavagetagguide.

ThisplasmidcontainstheIPTGinducIBLepromoterthatwascreatedbythefusionoftheLacpromoterandtheTryptophanoperonpromoter.ItallowsinducibleexpressioninE.coliusingIPTGastheinducingagent.

Thisplasmidcontainsann-terminalSTagepitopetagthatcanbefusedtoageneofinteresttoallowproteindetectionand/orpurification.Thesequenceofthetagis:KETAAAKFERQHMDS

Formoreinformationonthemethodsthatcanbeusedtopurifyproteinspleaseseeourproteintagguide.

ThisplasmidalsocontainsasecondaryHexa-Histidine(6His)proteintag.Thesequenceofthistagis:HHHHHH

Weprovidearangeofdualpeptidetagplasmids.ThisisbecausesomepeptidetagsprovidespecificBIOLOGicalproperties(e.gsmallmoleculeaffinitynewepitopessolubilityorproteinsecretion)thatarenotprovidedbyothers.

SequenceandMap:

OtherInfo:

ThisplasmidcontainsthreealternativetranscriptionterminatorsforTagT7LacOInduciblebacterialandbacteriophage(T7)expression.Thismeansthatonlythepromoterneedstobechangedtoaltertheexpressionsystemyouareusing.Wesellmultiplepromotersthatcanbeusedineachofthesesystems.Thepresenceofeachterminatordoesnotreduceexpressioninthealternativesystems.

Cloning:

ThisplasmidhasbeendesignedtoallowthreetypesofcloningintothemainMCStojoinacodingsequencewiththetag.

Thisplasmidhasbeendesignedtobecompatiblewitharangeofcloningtechniques.Themultiplecloningsitecontainsarangeofstandardcommonlyusedrestrictionsitesforcloning.UsingthesesitesgenescanbeinsertedusingstandardcloningmethodswithDNAligase.Othermethodssuchasligaseindependentcloning(LIC)GibsonAssemblyInFusionHDorSeamlessGeneArtcanalsobeusedandbecauseallofourplasmidsarebasedonthesamebackbonethesamemethodcanbeusedforcloningintoallofourcataloguevectors.

ThereareafewimportantsiteswithintheMCS.TheseincludetheNcoIsitetheXbaIsiteandtheBsgIandBseRIsites.TheNcoIsitecontainsastartcodonthatisimmediatelydownstreamofbothaKozakandShine-Dalgarnoribosomalbindingsite.Theseallowforoptimalpositioningofgeneswhenthestartcodonisplacedinthislocation.IfthisisnotrequiredandyouwishtouseadownstreamsiteforgenecloningyoucanremovetheNcoIsitebycleavingtheplasmidwithKpnI.

TheXbaIsitecontainsastopcodon.ThisstopcodonispositionedinaspecificpositioninrelationtotheBsgIandBseRIsitesthatareimmediatelydownstream.WheneitherBseRIorBsgIcleavetheplasmidtheyproduceaTAoverhangfromthestopcodonintheXbaIsitethatiscompatiblewithallofourpeptidetagplasmidscutwiththesamesites.BseRIandBsgIsitesarenon-palindromicandcleaveadefinednumberofbasesawayfromtheirbindingsite.

WheneverwecloneageneintoourmultiplecloningsitewealwayspositionthestartandstopcodoninthesamepositionsintheMCS.IfthestartandendsofthegenesarenotcompatiblewithNcoIandXbaIweextendthesequencetothenearestexternalsitesbutkeepthestartandstopcodonslocationsconsistent.

IfyouwouldliketofuseyourcodingsequencetothetagwithminimaladditionalbasesyoucanuseourSnapFusiontechnology.ThisprocessinvolvesamplifyingyourgenebyPCRtoaddspecificrestrictionsitesontotheends.WhenthesesitesarecuttheyproduceanoverhangthatiscompatiblewiththisplasmidcutwithBseRIorBsgI.

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.

Ifyouarenotconcernedaboutleavingafewextrabasesbetweenthetagcodingsequenceandyourgeneyoucancloneyourgeneintothevectorusingstandardcloningrestrictionenzymes.Thisstrategywillrequireyoutochoosewhichenzymesyouwanttousetocloneyourgene.

OpenthePrimerDesignToolwhichprovidesprimerswithdifferentenzymechoicespositioningyourgeneasclosetothetagaspossibleineachcase.Pleasenotethatstandardenzymeswillalwaysleaveadditionalnucleotidesbetweenyourgeneandthetagbutusingthespreadsheetwillensurethetagandgeneareinframe.

ThesecloningtechniquesusereagentssoldbyothercompaniesandallowyoutofusesequencestogetherusingenzymesthatchewbacktheDNAtoleaveoverlappingends/overhangs.ThesubsequentmethodofjoiningtheDNAdependsonthekitused.Touseoneofthesetechniquesyoucaneitherdesignyourownprimersoryoucanusethespreadsheetbelowtohelpwiththedesign.

OpenthePrimerDesignTooltohelpyoudesignprimersforcloningyourgeneusingGibsonassemblyInfusionHDGeneArtSeamlesscloningorLigaseIndependentCloning(LIC)techniques.

IPStatus:

ThisproductispartofourSnapFastplasmidrange,formoreinformationontheIntellectualpropertystatusofthisplasmidpleaseclickhere