Pterin-dependent biocatalysts and uses thereof

An engineered cell comprising:

• a biocatalyst, the biocatalyst comprising:
• a tetrahydrobiopterin source, wherein the tetrahydrobiopterin source is a tetrahydrobiopterin synthesis pathway comprising:
• a GTP cyclohydrase, wherein the GTP cyclohydrolase is encoded by a nucleotide sequence comprising SEQ ID NO:
• 1, SEQ ID NO:
• 2, SEQ ID NO:
• 3, or SEQ ID NO:
• 4;
• a pyruvoyl tetrahydropterin synthase, wherein the pyruvoyl tetrahydropterin synthase is encoded by a nucleotide sequence comprising SEQ ID NO:
• 5, SEQ ID NO:
• 6, SEQ ID NO:
• 7, or SEQ ID NO:
• 8;
• and
• a sepiapterin reductase, wherein the sepiapterin reductase is encoded by a nucleotide sequence comprising SEQ ID NO:
• 9, SEQ ID NO:
• 10, or SEQ ID NO:
• 11;
• and
• a pterin-dependent enzymatic pathway, wherein the pterin-dependent enzymatic pathway comprises tryptophan hydroxylase and aromatic-l-amino acid decarboxylase wherein the aromatic-1-amino acid decarboxylase is encoded by a nucleotide sequence comprising SEQ ID NO:17.

A biocatalyst comprising:

• a tetrahydrobiopterin source;
• a pterin-dependent enzymatic pathway, wherein the pterin-dependent enzymatic pathway comprises tryptophan hydroxylase encoded by a nucleotide sequence comprising SEQ ID NO:
• 15 and aromatic-l-amino acid decarboxylase;
• and
• a tetrahydrobiopterin recycling pathway, wherein the tetrahydrobiopterin recycling pathway comprises a pterin-4a-carbinolamine dehydratase and a dihydropterin reductase.