Characterization of putative tryptophan monooxygenase from Ralstonia solanacearum [corrected].
The amino-acid sequence of a putative tryptophan monooxygenase (PTMO) from Ralstonia solanacearum is homologous with that of proenzyme (proPAO) of l-Phe oxidase (deaminating and decarboxylating) (PAO) from Pseudomonas sp. P-501 in their overall sequences. PTMO was expressed in E. coli and purified, but had no catalytic activity to oxidize l-Phe. By treating PTMO with various proteases, the Pronase-treated PTMO (PTMOp) showed a relatively high activity to oxidize l-Phe, l-Trp, l-Tyr and l-Met. Studies on the stoichiometry of the reaction showed that l-Phe and l-Tyr were mostly oxygenated, that l-Met was mostly oxidized, and both oxygenation and oxidation of l-Trp was observed. Initial velocity patterns were a ping-pong type with l-Phe and l-Tyr, and a sequential type with l-Trp and l-Met as substrate. The spectrum of enzymes with sufficient amounts of these substrates to reduce the enzyme showed a long wavelength species (purple complex) with l-Phe, but not with l-Tyr, l-Trp and l-Met. These results lead to the conclusion that PTMO and PTMOp belong to proPAO and PAO, respectively.
Kurosawa
Nami
N
Department of Biosciences, Kitasato University, Sagamihara-shi, Kanagawa-ken, Japan.
Hirata
Tomoko
T
Suzuki
Haruo
H
D000594:Amino Acid Oxidoreductases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D003641:Deamination; D003653:Decarboxylation; D004792:Enzyme Precursors / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D005420:Flavoproteins; D007700:Kinetics; D008715:Methionine / Q000378:metabolism; D008961:Models, Structural; D008969:Molecular Sequence Data; D010649:Phenylalanine / Q000378:metabolism; D043368:Ralstonia solanacearum / Q000201:enzymology*; D016415:Sequence Alignment; D013379:Substrate Specificity / Q000502:physiology; D014169:Transformation, Bacterial; D014364:Tryptophan / Q000378:metabolism; D014365:Tryptophan Hydroxylase / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism
D001426:Bacterial Proteins; D004792:Enzyme Precursors; D005420:Flavoproteins; D014443:Tyrosine; D010649:Phenylalanine; D014364:Tryptophan; D008715:Methionine; D014365:Tryptophan Hydroxylase; D000594:Amino Acid Oxidoreductases; C022342:phenylalanine oxidase