If you use prokaryotic expression systems, there are plenty of ready-to-use plasmids which allow to insert the gene of interest in frame with what you need (look for example the pET series). If you need a step-by-step guide I can try to see if I find something in my folders, but I'm sure there are plenty of protocols you can access to.

If you don't have those plasmids nor the possibility to get them, you can "build" one by yourself, but it's quite a long process.

The simplest way would be to firstly write out the peptide sequence of what you are trying to generate. For instance :

M-HHHHHH-GSGSGS-MVSKGEELFTGVVPILVELDGDVNGHKFSVSGEGEGDATYGKLTLKFICTTGKLPVPWPTLVTTLTYGVQCFSRYPDHMKQHDFFKSAMPEGYVQERTIFFKDDGNYKTRAEVKFEGDTLVNRIELKGIDFKEDGNILGHKLEYNYNSHNVYIMADKQKNGIKVNFKIRHNIEDGSVQLADHYQQNTPIGDGPVLLPDNHYLSTQSKLSKDPNEKRDHMVLLEFVTAAGITLGMDELYK-GSGSG-ENLYFQG- your protein sequence

The above encodes - His tag, GS flexilinker, monomeric enhanced GFP - GS flexilinker - TEV protease site - your protein sequence.

Then ask a company that performs Gene synthesis to generate the above sequence as an E.coli-optimised sequence cloned into a pET vector.

Alternatively, as suggested by Emmanuele above, find an equivalent bacterial vector with the fusion components you are looking for and request your sequence to be generated and cloned into this.

If you need further advice, by all means come back here and I can be a bit more detailed.

Best wishes, Robin

Thank you Emmanuele and Robin