Deletion of amino acids 169 to 399, en-derived regions 2, 3 and 4 (removes both the R domain and the most conserved portion of eh1).
Deletion of amino acids 169-399, including an active repression domain of en and a conserved motif from the N-terminal half of en (en-derived regions 3 and 4).
Carried in plasmid "phs-EFEΔ" and expressed in S2 cells.
Carried in plasmid "pEFEΔ34", expressed in S2 cells and competition for ftz binding sites on a Ecol\CAT reporter plasmid is studied.