In addition to that, a co-expression system composed of 6 act earlier genes (KS-, CLP-, ACP-, KR-, ARO- and CYC-encoding genes) together with med-ORF12 could result in the production of (S)-DNPA 7, proposing that Med-ORF12 could catalyze a stereospecific ketoreduction at C3 of the bicyclic intermediate 4, formed by 6 act earlier genes [12, 19 ].
Source: wiktionary