PhhC is an essential aminotransferase for aromatic amino acid catabolism in Pseudornonas aeruginosa

Gu, Wei; Jiang, Song; Bonner, Carol A.; Xie, Gang; Jensen, Roy A.

doi:10.1099/00221287-144-11-3127

Cited by 26 publications

(27 citation statements)

References 26 publications

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“…The Function of CpPAH-In some prokaryotic organisms containing PAH the initial steps in a catabolic pathway to mediate Phe and Tyr carbon recycling involve the function of the phh operon and include the reactions L-Phe 3 L-Tyr (catalyzed by PAH) and L-Tyr 3 4-hydroxyphenylpyruvate (catalyzed by tyrosine aminotransferase) (64), similar to the steps for L-Phe catabolism in eukaryotes. 4-Hydroxyphenylpyruvate is then further oxidized to homogentisic acid (65).…”

Section: Discussionmentioning

confidence: 99%

Structure of Phenylalanine Hydroxylase from Colwellia psychrerythraea 34H, a Monomeric Cold Active Enzyme with Local Flexibility around the Active Site and High Overall Stability

Leiros

Pey

Innselset

et al. 2007

Journal of Biological Chemistry

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The characteristic of cold-adapted enzymes, high catalytic efficiency at low temperatures, is often associated with low thermostability and high flexibility. In this context, we analyzed the catalytic properties and solved the crystal structure of phenylalanine hydroxylase from the psychrophilic bacterium Colwellia psychrerythraea 34H (CpPAH). . Normal mode and COREX analysis also detect these and other areas with high flexibility. Greater mobility around the active site and disrupted hydrogen bonding abilities for the cofactor appear to represent cold-adaptive properties that do not markedly affect the thermostability of CpPAH.

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Section: Discussionmentioning

confidence: 99%

Structure of Phenylalanine Hydroxylase from Colwellia psychrerythraea 34H, a Monomeric Cold Active Enzyme with Local Flexibility around the Active Site and High Overall Stability

Leiros

Pey

Innselset

et al. 2007

Journal of Biological Chemistry

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“…COG2154 sequences were identified using the National Center for Biotechnology Information (NCBI) Conserved Domain (CD) search tool (Marchler-Bauer et al, 2005). For prokaryotes, the enzymes of the Tyr-catabolizing homogentisate pathway were included in the analysis because of the known catabolic role of P. aeruginosa Phe hydroxylase and PCD (Gu et al, 1998). The results are summarized in Figure 2 and given in detail in Supplemental Table S1.…”

Section: Phylogenomic Analysis Of Cog2154 In Plants and Microbesmentioning

confidence: 99%

“…Phe hydroxylases in animals and P. aeruginosa serve a catabolic function, converting Phe to Tyr (Fig. 1B) that can then be degraded via the homogentisate pathway (Gu et al, 1998;Arias-Barrau et al, 2004;Moran, 2005).…”

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confidence: 99%

Phylogenomic and Functional Analysis of Pterin-4a-Carbinolamine Dehydratase Family (COG2154) Proteins in Plants and Microorganisms

et al. 2008

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Pterin-4a-carbinolamine dehydratases (PCDs) recycle oxidized pterin cofactors generated by aromatic amino acid hydroxylases (AAHs). PCDs are known biochemically only from animals and one bacterium, but PCD-like proteins (COG2154 in the Clusters of Orthologous Groups [COGs] database) are encoded by many plant and microbial genomes. Because these genomes often encode no AAH homologs, the annotation of their COG2154 proteins as PCDs is questionable. Moreover, some COG2154 proteins lack canonical residues that are catalytically important in mammalian PCDs. Diverse COG2154 proteins of plant, fungal, protistan, and prokaryotic origin were therefore tested for PCD activity by functional complementation in Escherichia coli, and the plant proteins were localized using green fluorescent protein fusions. Higher and lower plants proved to have two COG2154 proteins, a mitochondrial one with PCD activity and a noncanonical, plastidial one without. Phylogenetic analysis indicated that the latter is unique to plants and arose from the former early in the plant lineage. All 10 microbial COG2154 proteins tested had PCD activity; six of these came from genomes with no AAH, and six were noncanonical. The results suggested the motif [EDKH]-x(3)-H-[HN]-[PCS]-x(5,6)-[YWF]-x(9)-[HW]-x(8,15)-D as a signature for PCD activity. Organisms having a functional PCD but no AAH partner include angiosperms, yeast, and various prokaryotes. In these cases, PCD presumably has another function. An ancillary role in molybdopterin cofactor metabolism, hypothesized from phylogenomic evidence, was supported by demonstrating significantly lowered activities of two molybdoenzymes in Arabidopsis thaliana PCD knockout mutants. Besides this role, we propose that partnerless PCDs support the function of as yet unrecognized pterin-dependent enzymes.

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“…The synthesis of Tyr is itself anabolic, but Tyr can be degraded via the homogentisate ring cleavage pathway to fumarate and acetoacetate and then to CO 2 . Phe hydroxylase-mediated funneling of Phe into the homogentisate pathway is well known in mammals and P. aeruginosa (Salter et al, 1986;Gu et al, 1998).…”

Section: Introductionmentioning

confidence: 99%

Nonflowering Plants Possess a Unique Folate-Dependent Phenylalanine Hydroxylase That Is Localized in Chloroplasts

et al. 2010

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Tetrahydropterin-dependent aromatic amino acid hydroxylases (AAHs) are known from animals and microbes but not plants. A survey of genomes and ESTs revealed AAH-like sequences in gymnosperms, mosses, and algae. Analysis of fulllength AAH cDNAs from Pinus taeda, Physcomitrella patens, and Chlamydomonas reinhardtii indicated that the encoded proteins form a distinct clade within the AAH family. These proteins were shown to have Phe hydroxylase activity by functional complementation of an Escherichia coli Tyr auxotroph and by enzyme assays. The P. taeda and P. patens AAHs were specific for Phe, required iron, showed Michaelian kinetics, and were active as monomers. Uniquely, they preferred 10-formyltetrahydrofolate to any physiological tetrahydropterin as cofactor and, consistent with preferring a folate cofactor, retained activity in complementation tests with tetrahydropterin-depleted E. coli host strains. Targeting assays in Arabidopsis thaliana mesophyll protoplasts using green fluorescent protein fusions, and import assays with purified Pisum sativum chloroplasts, indicated chloroplastic localization. Targeting assays further indicated that pterin-4a-carbinolamine dehydratase, which regenerates the AAH cofactor, is also chloroplastic. Ablating the single AAH gene in P. patens caused accumulation of Phe and caffeic acid esters. These data show that nonflowering plants have functional plastidial AAHs, establish an unprecedented electron donor role for a folate, and uncover a novel link between folate and aromatic metabolism.

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PhhC is an essential aminotransferase for aromatic amino acid catabolism in Pseudornonas aeruginosa

Cited by 26 publications

References 26 publications

Structure of Phenylalanine Hydroxylase from Colwellia psychrerythraea 34H, a Monomeric Cold Active Enzyme with Local Flexibility around the Active Site and High Overall Stability

Structure of Phenylalanine Hydroxylase from Colwellia psychrerythraea 34H, a Monomeric Cold Active Enzyme with Local Flexibility around the Active Site and High Overall Stability

Phylogenomic and Functional Analysis of Pterin-4a-Carbinolamine Dehydratase Family (COG2154) Proteins in Plants and Microorganisms

Nonflowering Plants Possess a Unique Folate-Dependent Phenylalanine Hydroxylase That Is Localized in Chloroplasts

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