1. Pseudomonas cepacia 2,2-dialkylglycine decarboxylase. Sequence and expression in Escherichia coli of structural and repressor genes.
- Author
-
Keller JW, Baurick KB, Rutt GC, O'Malley MV, Sonafrank NL, Reynolds RA, Ebbesson LO, and Vajdos FF
- Subjects
- Amino Acid Sequence, Base Sequence, Binding Sites, Cloning, Molecular, Codon, DNA, Bacterial biosynthesis, DNA, Bacterial genetics, Escherichia coli enzymology, Molecular Sequence Data, Ornithine-Oxo-Acid Transaminase, Pseudomonas genetics, Recombinant Proteins, Sequence Homology, Nucleic Acid, Carboxy-Lyases genetics, Escherichia coli genetics, Gene Expression drug effects, Genes, Bacterial genetics, Pseudomonas enzymology
- Abstract
A 3969-base pair PstI-PstI fragment of Pseudomonas cepacia DNA containing the gene for the pyridoxal 5'-phosphate dependent 2,2-dialkylglycine decarboxylase (pyruvate) (EC 4.1.1.64) was cloned in Escherichia coli. The insert was sequenced by the dideoxy method using nested deletions from both ends, revealing a central 1302-base pair region that codes for the decarboxylase subunit. The recombinant enzyme was expressed in E. coli, purified to homogeneity, and sequenced at the amino terminus. Also, a cofactor-labeled active site peptide was sequenced. The carboxyl terminus of the deduced amino acid sequence is homologous with the carboxyl terminus of mammalian ornithine aminotransferase; the active site sequence is similar to the active site sequences of several other aminotransferases. No homologies with known decarboxylase sequences could be found. Expression of the decarboxylase gene is negatively controlled by a 687-nucleotide sequence upstream of and diverging from the structural gene. Expression is induced by S-isovaline, 2-methylalanine, and D-2-aminobutanoic acid, but not by glycine, D- or L-alanine, L-2-aminobutanoic acid, R-isovaline, or other alkyl amino acids.
- Published
- 1990