Authors: SuHyun Kim MiAe Heo YuJin Kim SoYeon Kim Rameshkumar Neelamegam SunGu Lee
Publish Date: 2008/08/02
Volume: 13, Issue: 3, Pages: 366-
Abstract
Expression of recombinant proteins in Escherichia coli is often carried out at low temperatures so as to improve the solubility and stability of the expressed proteins However the use of low temperature significantly limits the growth rate of the expression host leading to a reduction in protein productivity Here we show that the introduction of the cspA 5′untranslated region cspA 5′UTR onto the transcript of a target gene enhances the expression levels via the T7 promoter at low temperatures First the effects of the cspA 5′UTR sequence and CspA coexpression on green fluorescence protein GFP production were investigated While the cspA 5′UTR sequence had no influence on the expression rate of GFP at 37°C it improved the expression level of GFP by approximately 15 fold at 15°C Coexpression of the CspA protein further increased the expression level of GFP only slightly in the presence of the cspA 5′UTR Subsequently the effect of the cspA 5′UTR on protein production was examined for six different proteins CysS HisS ProS ThrS TrpS and YadB at 15°C The introduction of cspA 5′UTR sequence led to approximate twofold improvement for HisS and ThrS production a slight improvement for TrpS and YadB and no influence on CysS and ProS protein production Therefore the effect of the cspA 5′UTR on the expression level at low temperature varied depending on the target gene
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