Polypeptides and biosynthetic pathways for the production of stereoisomers of monatin and their precursors

A method of producing monatin or salt thereof, the method comprising:

• producing indole-3-pyruvate (“I3P”) from L-tryptophan;
• producing monatin precursor (“MP”) including at least R monatin precursor (“R-MP”) from the I3P;
• and
• producing the monatin from the MP, wherein:
• at least about 60% by weight of total monatin produced is R,R monatin;
• the production of the I3P from the L-tryptophan is facilitated by one or more first enzymes having greater activity, greater specificity, or both, for L-tryptophan than for the monatin precursor, the monatin, or both, said one or more first enzymes are chosen from an L-tryptophan aminotransferase, an L-aromatic aminotransferase, an L-aspartate aminotransferase, and an L-amino acid oxidase, and combinations thereof;
• the production of the monatin precursor from the I3P is facilitated by one or more second enzymes having R-specific aldolase activity;
• and
• wherein said R,R monatin production from said R-MP is facilitated by one or more third enzymes chosen from a D-aminotransferase and a D-amino acid dehydrogenase or combinations thereof.