title: PhhC is an essential aminotransferase for aromatic amino acid catabolism in Pseudomonas aeruginosa.
abstract: The phhC gene of Pseudomonas aeruginosa encodes a protein which is a member of the Family I aminotransferases. At high expression levels in the heterologous Escherichia coli system, PhhC can compensate for the absence of AspC (which functions in L-aspartate biosynthesis) and TyrB (which functions in aromatic biosynthesis). In the native organism, PhhC is essential for catabolism of either L-tyrosine or L-phenylalanine, as demonstrated by gene inactivation. This catabolic function of PhhC is consistent with its inclusion as the distal gene in the inducible phenylalanine hydroxylase operon. The presence of PhhC for catabolism of aromatic amino acids is required in spite of an existing multiplicity of other P. aeruginosa aminotransferases having a similar pattern of broad substrate specificity in vitro. This implies a spatial orientation of PhhC that effectively specializes it for aromatic amino acid catabolism.
authors.affiliation: Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 3261 1-0700, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Gu
authors.affiliation: Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 3261 1-0700, USA.
authors.forename: Jian
authors.initials: J
authors.lastname: Song
authors.affiliation: Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 3261 1-0700, USA.
authors.forename: Carol A
authors.initials: CA
authors.lastname: Bonner
authors.affiliation: Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 3261 1-0700, USA.
authors.forename: Gang
authors.initials: G
authors.lastname: Xie
authors.affiliation: Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 3261 1-0700, USA.
authors.forename: Roy A
authors.initials: RA
authors.lastname: Jensen
mesh_terms: D000595:Amino Acid Sequence; D015139:Blotting, Southern; D015153:Blotting, Western; D002384:Catalysis; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000201:enzymology; D016254:Mutagenesis, Insertional; D009876:Operon; D010649:Phenylalanine / Q000378:metabolism*; D010651:Phenylalanine Hydroxylase / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D011550:Pseudomonas aeruginosa / Q000201:enzymology* / Q000235:genetics; D017422:Sequence Analysis, DNA; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013379:Substrate Specificity; D000637:Transaminases / Q000235:genetics* / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism*
chemical_list: D014443:Tyrosine; D010649:Phenylalanine; D010651:Phenylalanine Hydroxylase; D000637:Transaminases