High throughput construction and small scale expression screening of multi-tag vectors in Escherichia coli

► A suite of N-terminal hexa-histidine tagged fusion protein vectors is presented. ► 9 fusion proteins can be made from one PCR product using Infusion™ cloning. ► The effect of fusions on the solubility of 20 proteins in E coli was tested in 2 media. ► The SUMO tag was the most effective at solubilising targets. ► Auto-induction media gave more high level expressers than IPTG induction. A suite of protein fusion vectors is presented that has been designed so that nine separate fusion vectors can be constructed from one PCR product using InFusion™ cloning. These vectors in combination with a small scale Escherichia coli expression screen can be used to assess in parallel the effect of fusion tags on solubility. The vectors were tested with 20 target proteins and the results suggest that the vectors are useful both as a rescue strategy if the N-terminal hexa-histidine tagged construct does not express and also as part of a primary expression experiment.