Degradation of purines and pyrimidines by microorganisms.

Vogels, Godfried D.; Drift, Chris van der

doi:10.1128/mmbr.40.2.403-468.1976

Cited by 373 publications

(203 citation statements)

References 231 publications

(415 reference statements)

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“…Since uric acid is introduced into the puddles from above, whether directly in feces or indirectly in oxygen-rich rain washing desiccated excreta from the rocks, aerobic uric acid decomposition will take place. Anaerobic decomposition, too, will take place, and also result in the formation of ammonia (Vogels and van der Drift 1976). I found that the aerobes capable of decomposing uric acid were more numerous than the anaerobes (Lindeboom 1979).…”

Section: Nitrogen Transformation In Thementioning

confidence: 98%

The Nitrogen Pathway in a Penguin Rookery

Lindeboom¹

1984

Ecology

182

121

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The most important nitrogen sources for the Marion Island ecosystem are the excreta of birds that forage at sea. Eighty percent of the nitrogen excreted by penguins during their molt fast appeared to be uric acid, with the remaining 20% mainly proteins and ammonia. The uric acid is rapidly degraded by aerobic and anaerobic microorganisms, and no uric acid could be detected in the penguin rookery deposit. Nitrification, followed by denitrification, occurs in the rookery deposit. However, laboratory experiments showed that both nitrification and denitrification are relatively unimportant processes in the rookery. Models of the nitrogen cycle in both a Macaroni Penguin and a King Penguin rookery during the molt fast and breeding season are given. In both rookeries the degradation of uric acid into ammonia and the subsequent evaporation are, quantitatively, the most important processes. The ammonia production in the rookeries of Macaroni Penguins as well as the heavy rains and the predominantly westerly winds have produced an "ammonia shadow" around the rookery where a vigorous plant growth occurs. The vegetation has formed a thick peat layer around the penguin rookery. 14C dating of this peat layer has shown that the Macaroni Penguins first bred on Marion Island °7000 yr ago.

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Section: Nitrogen Transformation In Thementioning

confidence: 98%

The Nitrogen Pathway in a Penguin Rookery

Lindeboom¹

1984

Ecology

182

121

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“…Subsequently, de novo and salvage pathways for purine biosynthesis are important components in the metabolism of all organisms. The ability to degrade purine compounds, either aerobically or anaerobically, has been identified in all kingdoms [19]. The aerobic degradation of purines is dependent on the oxidation of hypoxanthine and xanthine to uric acid via xanthine dehydrogenase ⁄ oxidase (E.C.…”

Section: The Function Of Tlp In Purine Metabolismmentioning

confidence: 99%

Evolutionary changes to transthyretin: structure and function of a transthyretin‐like ancestral protein

Hennebry

2009

The FEBS Journal

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The structure of the thyroid hormone distributor protein, transthyretin, has been highly conserved during the evolution of vertebrates. Over the last decade, studies into the evolution of transthyretin have revealed the existence of a transthyretin homolog, transthyretin‐like protein, in all kingdoms. Phylogenetic studies have suggested that the transthyretin gene in fact arose as a result of a duplication of the transthyretin‐like protein gene in early protochordate evolution. Structural studies of transthyretin‐like proteins from various organisms have revealed the remarkable conservation of the transthyretin‐like protein/transthyretin fold. The only significant differences between the structures of transthyretin‐like protein and transthyretin were localized to the dimer–dimer interface and indicated that thyroid hormones could not be bound by transthyretin‐like protein. All transthyretin‐like proteins studied to date have been demonstrated to function in purine metabolism by hydrolysing the oxidative product of uric acid, 5‐hydroxyisourate. The residues characterizing the catalytic site in transthyretin‐like proteins are 100% conserved in all transthyretin‐like protein sequences but are absent in transthyretins. Therefore, it was proposed that following duplication of the transthyretin‐like protein gene, loss of these catalytic residues resulted in the formation of a deep, negatively charged channel that runs through the centre of the transthyretin tetramer. The results thus demonstrate the remarkable evolution of the transthyretin‐like protein/transthyretin protein from a hydrolytic enzyme to a thyroid hormone distributor protein.

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“…Interestingly, annotation of the DNA sequences flanking the Jannaschia sp. CCS1 HYD Js revealed an ORF encoding a putative allantoate amidohydrolase, which is part of the urate catabolic pathway in many organisms [8]. In fact, by genome data mining, another hydantoinase (HYD) was also found in the Jannaschia sp.…”

Section: Discussionmentioning

confidence: 99%

Isolation and molecular characterization of a novel d‐hydantoinase from Jannaschia sp. CCS1

et al. 2009

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Hydantoinases (HYDs) are important enzymes for industrial production of optically pure amino acids, which are widely used as precursors for various semi‐synthetic antibiotics. By a process coupling genomic data mining with activity screening, a new hydantoinase, tentatively designated HYDJs, was identified from Jannaschia sp. CCS1 and overexpressed in Escherichia coli. The specific activity of HYDJs on d,l‐p‐hydroxyphenylhydantoin as the substrate was three times higher than that of the hydantoinase originating from Burkholderia pickettii (HYDBp) that is currently used in industry. The enzyme obtained was a homotetramer with a molecular mass of 253 kDa. The pH and temperature optima for HYDJs were 7.6 and 50 °C respectively, similar to those of HYDBp. Kinetic analysis showed that HYDJs has a higher kcat value on d,l‐p‐hydroxyphenylhydantoin than HYDBp does. Homology modeling and substrate docking analyses of HYDJs and HYDBp were performed, and the results revealed an enlarged substrate binding pocket in HYDJs, which may allow better access of substrates to the catalytic centre and could account for the increased specific activity of HYDJs. Three amino acid residues critical for HYDJs activity, Phe63, Leu92 and Phe150 were also identified by substrate docking and site‐directed mutagenesis. Application of this high‐specific activity HYDJs could improve the industrial production of optically pure amino acids, such as d‐p‐hydroxyphenylglycine. Moreover, the structural analysis also provides new insights on enzyme–substrate interaction, which shed light on engineering of hydantoinases for high catalytic activity.

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Degradation of purines and pyrimidines by microorganisms.

Abstract: 435 436 437 438 438 439 439 440 440 441 441 442 444 445 446 447 447 447 448 448 448 449 449 449 449 BACTERIOL. RHv.

Cited by 373 publications

References 231 publications

The Nitrogen Pathway in a Penguin Rookery

The Nitrogen Pathway in a Penguin Rookery

Evolutionary changes to transthyretin: structure and function of a transthyretin‐like ancestral protein

Isolation and molecular characterization of a novel d‐hydantoinase from Jannaschia sp. CCS1

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