Expression in E. coli of the gene encoding phenylalanine ammonia-lyase from Rhodosporidium toruloides

The active sites of the enzyme phenylalanine ammonia-lyase (Pal) from Rhodosporidium toruloides contains a dehydroalanine residue that is believed to be essential for catalytic activity. Furthermore, the dehydroalanine is believed to be added post-translationally as part of a prosthetic group covalently attached to the enzyme. Perhaps for this reason no attempts to produce Pal in foreign host cells have been reported. We have inserted the entire uninterupted pal gene from R. toruloides into the Escherichia coli expression vector pKK 223-3. E. coli cells containing this vector synthesize a protein of the expected size, and extracts prepared from these cells contain a Pal-like activity. The potential implications of this finding are discussed.