Expression of polypeptides involved in lysine decarboxylation, and methods and applications thereof

A product, selected from the group consisting of:

• I) a transformant comprising an expression plasmid vector in a host cell that is not a Pseudomonas aeruginosa (P. aeruginosa) cell, the expression plasmid vector comprising:
• a polynucleotide encoding one or more polypeptides, each polypeptide consisting of the amino acid sequence of a mutant of SEQ ID NO:
• 4 (lysine decarboxylase (Ldc2));
• and a backbone plasmid capable of autonomous replication in the host cell,
• wherein the mutant of SEQ ID NO:4 (Ldc2) is selected from the group consisting of the amino acid sequences of SEQ ID NO:
• 6 (Ldc2 S111C), SEQ ID NO:
• 11 (Ldc2 N262T), SEQ ID NO:
• 12 (Ldc2 K265N), SEQ ID NO:
• 13 (Ldc2 S111C/N262T), SEQ ID NO:
• 14 (Ldc2 S111C/K265N), SEQ ID NO:
• 15 (Ldc2 N262T/K265N), and SEQ ID NO:
• 16 (Ldc2 S111C/N262T/K265N);
• II) an expression plasmid vector comprising:
• a polynucleotide encoding one or more polypeptides, each polypeptide consisting of the amino acid sequence of a mutant of SEQ ID NO:
• 4 (Ldc2);
• and a backbone plasmid capable of autonomous replication in a host cell, wherein the host cell is not a P. aeruginosa cell,
• wherein the mutant of SEQ ID NO:4 (Ldc2) is selected from the group consisting of the amino acid sequences of SEQ ID NO:
• 6 (Ldc2 S111C), SEQ ID NO:
• 11 (Ldc2 N262T), SEQ ID NO:
• 12 (Ldc2 K265N), SEQ ID NO:
• 13 (Ldc2 S111C/N262T), SEQ ID NO:
• 14 (Ldc2 S111C/K265N), SEQ ID NO:
• 15 (Ldc2 N262T/K265N), and SEQ ID NO:
• 16 (Ldc2 S111C/N262T/K265N);
• III) a first mutant host cell comprising a polynucleotide integrated into a chromosome of the host cell, wherein the polynucleotide encodes one or more polypeptides, each polypeptide consisting of the amino acid sequence of a mutant of SEQ ID NO:
• 4 (Ldc2),
• wherein the mutant of SEQ ID NO:4 (Ldc2) is selected from the group consisting of the amino acid sequences of SEQ ID NO:
• 6 (Ldc2 S111C), SEQ ID NO:
• 11 (Ldc2 N262T), SEQ ID NO:
• 12 (Ldc2 K265N), SEQ ID NO:
• 13 (Ldc2 S111C/N262T), SEQ ID NO:
• 14 (Ldc2 S111C/K265N), SEQ ID NO:
• 15 (Ldc2 N262T/K265N), and SEQ ID NO:
• 16 (Ldc2 S111C/N262T/K265N);
• IV) a non-naturally occurring polynucleotide encoding a polypeptide consisting of the amino acid sequence of a mutant of SEQ ID NO:
• 4, wherein the mutant of SEQ ID NO:
• 4 is selected from the group consisting of the amino acid sequences of SEQ ID NO:
• 6 (Ldc2 S111C), SEQ ID NO:
• 11 (Ldc2 N262T), SEQ ID NO:
• 12 (Ldc2 K265N), SEQ ID NO:
• 13 (Ldc2 S111C/N262T), SEQ ID NO:
• 14 (Ldc2 S111C/K265N), SEQ ID NO:
• 15 (Ldc2 N262T/K265N), and SEQ ID NO:
• 16 (Ldc2 S111C/N262T/K265N);
• and
• V) a non-naturally occurring polynucleotide comprising the polynucleotide sequence of a mutant of SEQ ID NO:
• 17.