Identification of an L-dopa decarboxylase gene from Sorangium cellulosum So ce90.

During a screening program intended to identify genes encoding enzymes typical for secondary metabolism in Sorangium cellulosum So ce90, an aromatic amino acid decarboxylase gene (ddc) was detected. Expression of ddc in Escherichia coli and subsequent enzyme assays with cell-free extracts confirmed the proposed function derived from amino acid sequence comparisons. In contrast to other aromatic amino acid decarboxylases of eukaryotic origin, the S. cellulosum Ddc converted only L-dihydroxy phenylalanine. This is the first report of a gene encoding an L-dihydroxy phenylalanine decarboxylase in bacteria.