![BL21(DE3)[pLysE]](https://pda.biobw.org/static/images/no_picture.jpg)
Species:Escherichia coli
Group:B
Strain designation:BL21(DE3)[pLysE]
Accession number:LMBP 2468
Depositor:Prof.Dr W.Studier1
1 Biology Department,Brookhaven National Laboratory,Upton,USA
Containment level:This strain has been assigned the containment level Class 1 following the European Directive 2009/41/EC on the contained use of genetically modified organisms,and its updates(see also the Belgian risk group classification).
Medium:LB-Lennox
Selection marker:chloramphenicol(34μg/ml)
Temperature:28°C
Genotype:F(-)ompT gal dcm lon hsdSB(rB(-)mB(-))λ(DE3[lacI lacUV5-T7 gene 1 ind1 sam7 nin5])
Phenotype:CamR
Properties:The strain contains DE3,aλprophage carrying the T7 RNA polymerase gene under control of the lac UV5 promoter and lacIq.IPTG is required to induce expression of the T7 RNA polymerase.Protein expression from transforming plasmids containing a T7 promoter-driven expression system is repressed until IPTG induction of T7 RNA polymerase expression occurs.The strain does not contain the lon protease and is also deficient in the outer membrane protease,OmpT.The lack of two key proteases reduces the degradation of heterologous proteins expressed in the strain.The helper plasmid pLysE produces higher amounts of T7 lysozyme than pLysS to further reduce basal level expression of recombinant genes by inhibiting basal levels of T7 RNA polymerase.This makes BL21(DE3)[pLysE]more suitable for expressing toxic genes.pLysE also carries the chloramphenicol resistance gene and the p15A origin for compatibility with plasmids containing the ColE1 or pMB1 origin.
Further information:The full genome sequence of the BL21(DE3)strain is available at the ENA/GenBank nucleotide sequence databases under accession number CP001509.3.
Original reference:Studier,J.Mol.Biol.219(1991),37-44[PMID:2023259][DOI:10.1016/0022-2836(91)90855-z]
Related reference:Daegelen et al.,J.Mol.Biol.394(2009),634-643[PMID:19765591][DOI:10.1016/j.jmb.2009.09.022]
Jeong et al.,J.Mol.Biol.394(2009),644-652[PMID:19786035][DOI:10.1016/j.jmb.2009.09.052]
Studier et al.,J.Mol.Biol.394(2009),653-680[PMID:19765592][DOI:10.1016/j.jmb.2009.09.021]
Studier and Moffatt,J.Mol.Biol.189(1986),113-130[PMID:3537305][DOI:10.1016/0022-2836(86)90385-2]
Restricted use:-BCCM MTA
Refer in your Materials and Methods:
Escherichia coli B BL21(DE3)[pLysE](LMBP 2468)is available at BCCM/GeneCorner.It was deposited by Prof.Dr W.Studier and was published in Studier,1991.
Group:B
Strain designation:BL21(DE3)[pLysE]
Accession number:LMBP 2468
Depositor:Prof.Dr W.Studier1
1 Biology Department,Brookhaven National Laboratory,Upton,USA
Containment level:This strain has been assigned the containment level Class 1 following the European Directive 2009/41/EC on the contained use of genetically modified organisms,and its updates(see also the Belgian risk group classification).
Medium:LB-Lennox
Selection marker:chloramphenicol(34μg/ml)
Temperature:28°C
Genotype:F(-)ompT gal dcm lon hsdSB(rB(-)mB(-))λ(DE3[lacI lacUV5-T7 gene 1 ind1 sam7 nin5])
Phenotype:CamR
Properties:The strain contains DE3,aλprophage carrying the T7 RNA polymerase gene under control of the lac UV5 promoter and lacIq.IPTG is required to induce expression of the T7 RNA polymerase.Protein expression from transforming plasmids containing a T7 promoter-driven expression system is repressed until IPTG induction of T7 RNA polymerase expression occurs.The strain does not contain the lon protease and is also deficient in the outer membrane protease,OmpT.The lack of two key proteases reduces the degradation of heterologous proteins expressed in the strain.The helper plasmid pLysE produces higher amounts of T7 lysozyme than pLysS to further reduce basal level expression of recombinant genes by inhibiting basal levels of T7 RNA polymerase.This makes BL21(DE3)[pLysE]more suitable for expressing toxic genes.pLysE also carries the chloramphenicol resistance gene and the p15A origin for compatibility with plasmids containing the ColE1 or pMB1 origin.
Further information:The full genome sequence of the BL21(DE3)strain is available at the ENA/GenBank nucleotide sequence databases under accession number CP001509.3.
Original reference:Studier,J.Mol.Biol.219(1991),37-44[PMID:2023259][DOI:10.1016/0022-2836(91)90855-z]
Related reference:Daegelen et al.,J.Mol.Biol.394(2009),634-643[PMID:19765591][DOI:10.1016/j.jmb.2009.09.022]
Jeong et al.,J.Mol.Biol.394(2009),644-652[PMID:19786035][DOI:10.1016/j.jmb.2009.09.052]
Studier et al.,J.Mol.Biol.394(2009),653-680[PMID:19765592][DOI:10.1016/j.jmb.2009.09.021]
Studier and Moffatt,J.Mol.Biol.189(1986),113-130[PMID:3537305][DOI:10.1016/0022-2836(86)90385-2]
Restricted use:-BCCM MTA
Refer in your Materials and Methods:
Escherichia coli B BL21(DE3)[pLysE](LMBP 2468)is available at BCCM/GeneCorner.It was deposited by Prof.Dr W.Studier and was published in Studier,1991.
