Collectively, the pGEX vectors provide all three translational reading frames beginning with an EcoRI restriction site. Some vectors have an expanded multiple cloning site (MCS) that contains six restriction sites. The expanded MCS facilitates the unidirectional cloning of cDNA inserts obtained from libraries constructed using many available lambda vectors. pGEX-6P-1, pGEX-6P-2, and pGEX-6P-3 each encode the recognition sequence for site-specific cleavage by PreScission Protease, (see PreScission Protease) between the GST domain and the multiple cloning site. pGEX-4T-2, and pGEX-4T-3 are derived from pGEX-2T and contain a Thrombin recognition site.

• A tac promoter for chemically inducible, high-level expression of GST-tagged recombinant proteins
• An internal lacIq gene for use in any E. coli host
• Very mild elution conditions for release of fusion proteins from the affinity matrix, thus minimising effects on antigenicity and functional activity
• PreScission Protease, Thrombin, or Factor Xa recognition sites for cleaving the desired protein from the fusion product