Maps of the plasmid vectors used for L-AA genes expression. pKlJC/GME (B) and pKlVTc (C) vectors are derived from pKLAC1 (A). The vectors contain the 5´ and 3´ ends of the LAC4 promoter separated by DNA encoding β-lactamase (AmpR) and the pMB1 origin (ori). Plasmid pKlVTc contains a construct where the yeast ADH1 promoter drives expression of an acetamidase selectable marker gene (amdS), which is flanked by hisG direct repeats. ADH1 and GPD1 promoters from Saccharomyces cerevesiae drive the transcription of AtVTC4 and AtVTC2 respectively. Plasmid pKLJC/GME contains the LoxP-KanMX-LoxP cassette that confers resistance to geneticin.