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Figure 1 | Microbial Cell Factories

Figure 1

From: Facile promoter deletion in Escherichia coli in response to leaky expression of very robust and benign proteins from common expression vectors

Figure 1

Small scale expression tests of individual clones in a lacIq+or lacIq-background. (A) Expression test of 10 clones each of the DARPins E3_5 and G3 in E. coli RV308 (lacIq-) from expression vector pMPAG77 (lacIq-). MW, molecular weight marker; U, uninduced, number, clone number induced with IPTG. No protein band of the correct size in 15% SDS-PAGE analysis could be observed. Instead, a prominent band of ~19 kDa of a host protein was observed upon induction with IPTG (black arrow), which was identified as E. coli Dps. (B) Expression of DARPins E3_5 and G3 (two individual clones each) in E. coli DH5α (lacIq-) can only be observed in 15% SDS-PAGE analysis if LacI is provided by the expression plasmid. U, uninduced; I, induced with IPTG.

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Microbial Cell Factories

ISSN: 1475-2859

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