菌株簡介
BL21 Star (DE3) E. coli are chemically competent cells designed for applications that require high-level expression of non-toxic recombinant proteins from low copy number, T7 promoter-based expression systems (e.g., Champion? pET vectors). BL21 Star (DE3) Chemically Competent cells are controlled for a transformation efficiency of 1 x 108 cfu/μg plasmid DNA. ? A genotype that promotes high mRNA stability and protein yield ? Ideal for use with low copy number, T7 promoter-based plasmids ? The single tube, single use format allows all transformation steps to take Enhanced Expression of Non-Toxic Recombinant Proteins BL21 Star (DE3) cells contain the DE3 lysogen that carries the gene for T7 RNA polymerase under control of the lacUV5 promotor, and IPTG is required to induce expression. This strain also offers enhanced mRNA stability due to a mutation in the RNaseE gene (rne131), which reduces levels of endogenous RNases and mRNA degradation, thereby increasing the stability of mRNA transcripts and increasing protein yield. Protein expression is further enhanced by the absence of the lon and outer membrane (OmpT) proteases, which reduces degradation of heterologous proteins. The BL21 Star strains have higher basal expression of heterologous genes than BL21 strains, due to the increased stability of mRNA. Therefore, these strains may not be useful for expression of toxic genes. BL21 Star(DE3)來源于BL21(DE3)菌株, 含有rne131基因突變體，rne131突變基因能夠增強(qiáng)菌株細(xì)胞內(nèi)mRNA的穩(wěn)定性，從而有效提高蛋白表達(dá)能力。 主要適用于T7啟動子載體的高水平蛋白表達(dá)。
