Mutated histidine decarboxylase and use thereof

A polynucleotide encoding a mutated histidine decarboxylase wherein said mutated histidine decarboxylase comprises a motif selected from the group consisting of:

• A) Motif (1):
• GDWX1X2X3CNYX4 motif (SEQ ID No:
• 8), where X1 is A, S, or G;
• X2 is E, A, or D;
• X3 is Y or E, and X4 is L or R,
• B) Motif (2):
• EX5NX6X7X8CYLX9 motif (SEQ ID No:
• 9), where X5 is S or G, X6 is M or L, X7 is F or Y, X8 is G or S, and X9 is G, S, or A,
• C) Motif (3):
• GSRNGX10TPX11X12MWX13AX14X15S motif (SEQ ID No:
• 10), where X10 is H or Q, X11 is L or M, X12 is M or I, X13 is C, E or A, X14 is V or I, and X15 is K or R,
• D) Motif (4):
• GX16X17AWX18X19 motif (SEQ ID No:
• 11), where X16 is I or V, X17 is N, D, Q, H, or P, X18 is C, R, or L, and X19 is N, H, or C,
• E) Motif (5):
• TVX20FPCPSX21X22 motif (SEQ ID No:
• 12), where X20 is V or I, X21 is E, V, or A, and X22 is A, D, S, or N,
• F) Motif (6):
• VWKX23X24CLAX25S motif (SEQ ID No:
• 13), where X23 is K or R, X24 is H or Y, and X25 is T or I, and
• G) combinations thereof;
• wherein at least one amino acid residue in the selected motif is mutated as compared to a wild-type histidine decarboxylase;
• wherein said mutated histidine decarboxylase has higher histidine decarboxylase activity and/or stability than a wild-type histidine decarboxylase;
• wherein the wild-type histidine decarboxylase comprises SEQ ID No:
• 3;
• and
• wherein said mutated histidine decarboxylase comprises an amino acid sequence having at least 90% or more amino acid sequence identity to the amino acid sequence of the wild-type histidine decarboxylase.