Fig. 1

Tet-On based P2A-mediated polycistronic expression system for A. niger. a Protein sequences of the P2A peptide and the putatively non-functional P2A peptide are given. For the latter, the final C-terminal amino acid proline was exchanged for an alanine. General design of the Tet-On system has been described earlier [26]. Order of genes and abbreviations used for the A. niger transformants made are described in the main text. b Schematic illustration of the proteins produced by ribosomal translation and position of the 2A added tags at the N- or C-terminal ends of the proteins