Phosphonolipids: Localization in Surface Membranes of
            <i>Tetrahymena</i>

Kennedy, Kathleen E.; Thompson, Guy A.

doi:10.1126/science.168.3934.989

Cited by 74 publications

(40 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The biosynthesis of the C-P bond has been documented in protozoa, fungi, and molluscs (16, 37). The importance of C-P bonds in these invertebrates is underscored by the observation that 50 to 75% of the cilia phospholipids of Tetrahymena are phosphonolipids (22).Given the biosynthetic accessibility of the C-P linkage it is almost axiomatic that bacteria would have evolved the ability to catabolize phosphonic acids. Indeed, by enrichment culture bacteria have been obtained that utilize 2-aminoethylphosphonic acid, the most abundant naturally occurring phosphonic acid, as the sole source of phosphorus, nitrogen, and carbon (4).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Bacterial carbon-phosphorus lyase: products, rates, and regulation of phosphonic and phosphinic acid metabolism

Wackett¹,

Shames²,

Venditti³

et al. 1987

J Bacteriol

169

115

View full text Add to dashboard Cite

Carbon-phosphorus bond cleavage activity, found in bacteria that utilize alkyl-and phenylphosphonic acids,has not yet been obtained in a cell-free system. Given this constraint, a systematic examination of in vivo C-P lyase activity has been conducted to develop insight into the C-P cleavage reaction. Six bacterial strains were obtained by enrichment culture, ideptified, and characterized with respect to their phosphonic acid substrate specificity. One isolate, Agrob4acterium radiobacter, was shown to cleave the carbon-phosphorus bond of a wide range of substrates, including fosfomycin, glyphosate, and dialkyl phosphinic acids. Furthermore, this organism processed vinyl-, propenyl-, and prQpynylphosphonic acids, a previously uninvestigated group, to ethylene, propene, and propyne, respectively. A determination of product stoichiometries revealed that both C-P bonds of dimethylphosphinic acid are cleaved quantitatively to methane and, furthermore, that the extent of C-P bond cleavage correlated linearly with the specific growth rate for a range of substrates. The broad substrate specificity of Agrobacterium C-P lyase and the comprehensive characterization of the in vivo activity make this an attractive system for further biochemical and mechanistic experiments. In addition, the failure to observe the activity in a group of gram-positive bacteria holds open the possibility that a periplasmic component may be required for in vivo expression of C-P lyase activity.Living systems contain organophosphorus mostly in the form of oxygen esters, diesters, and anhydrides of phosphoric acid. However, phosphonic acids, a class of organophosphorus compounds containing a direct carbon-phosphorus bond, are also found in nature (14, 21). The initial discovery of a natural phosphonic acid product, 2-aminoethylphosphonic acid, in 1959 (18) is relatively recent compared with the history of research in biological organophosphate esters. Since that time dozens of naturally occurring C-P compounds have been discovered (17). The biosynthesis of the C-P bond has been documented in protozoa, fungi, and molluscs (16, 37). The importance of C-P bonds in these invertebrates is underscored by the observation that 50 to 75% of the cilia phospholipids of Tetrahymena are phosphonolipids (22).Given the biosynthetic accessibility of the C-P linkage it is almost axiomatic that bacteria would have evolved the ability to catabolize phosphonic acids. Indeed, by enrichment culture bacteria have been obtained that utilize 2-aminoethylphosphonic acid, the most abundant naturally occurring phosphonic acid, as the sole source of phosphorus, nitrogen, and carbon (4). The biochemistry of this process was first investigated in Bacillus cereus, where 2-aminoethylphosphonic acid was shown to undergo transamination to yield phosphonoacetaldehyde followed by hydrolysis to acetaldehyde and Pi (25). The hydrolytic cleavage step is catalyzed by phosphonoacetaldehyde hydrolyase (26), an enzyme given the trivial name of phosphonatase (equation 1).2-phosphonatase OHCCH...

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

Bacterial carbon-phosphorus lyase: products, rates, and regulation of phosphonic and phosphinic acid metabolism

Wackett¹,

Shames²,

Venditti³

et al. 1987

J Bacteriol

169

115

View full text Add to dashboard Cite

show abstract

“…In these organisms, Pn have been isolated as constituents of glycolipids, glycoproteins, polysaccharides, or phosphonolipids. In Bacteroides fragilis, Pn were identified as components of capsular polysaccharide (6); in streptomycetes, Pn are synthesized as antibiotics such as fosfomycin (25); in Tetrahymena spp., Pn exist as phosphonolipids (19); in Trypanosoma cruzi, Pn are components of lipopeptidophosphoglycan (the major cell surface glycoconjugate [10]); in a sea anemone, Pn are the major P compounds (38); and in a locus, a Pn is the principal P compound of hemolymph (20). Yet, in spite of their widespread natural occurrence, the biological role of natural Pn is poorly understood (17).…”

mentioning

confidence: 99%

Molecular cloning, mapping, and regulation of Pho regulon genes for phosphonate breakdown by the phosphonatase pathway of Salmonella typhimurium LT2

et al. 1995

View full text Add to dashboard Cite

Two pathways exist for cleavage of the carbon-phosphorus (C-P) bond of phosphonates, the C-P lyase and the phosphonatase pathways. It was previously demonstrated that Escherichia coli carries genes (named phn) only for the C-P lyase pathway and that Enterobacter aerogenes carries genes for both pathways (K.-S. Lee, W. W. Metcalf, and B. L. Wanner, J. Bacteriol. 174:2501-2510, 1992). In contrast, here it is shown that Salmonella typhimurium LT2 carries genes only for the phosphonatase pathway. Genes for the S. typhimurium phosphonatase pathway were cloned by complementation of E. coli ⌬phn mutants. Genes for these pathways were proven not to be homologous and to lie in different chromosomal regions. The S. typhimurium phn locus lies near 10 min; the E. coli phn locus lies near 93 min. The S. typhimurium phn gene cluster is about 7.2 kb in length and, on the basis of gene fusion analysis, appears to consist of two (or more) genes or operons that are divergently transcribed. Like that of the E. coli phn locus, the expression of the S. typhimurium phn locus is activated under conditions of P i limitation and is subject to Pho regulon control. This was shown both by complementation of the appropriate E. coli mutants and by the construction of S. typhimurium mutants with lesions in the phoB and pst loci, which are required for activation and inhibition of Pho regulon gene expression, respectively. Complementation studies indicate that the S. typhimurium phn locus probably includes genes both for phosphonate transport and for catalysis of C-P bond cleavage.Phosphonates (Pn) are a large class of molecules containing a direct carbon-phosphorus (C-P) bond in place of the more familiar carbon-oxygen-phosphorus bond of phosphoesters. Although Pn do not exist in all organisms, they do exist in many different ones. Pn have been found in organisms as diverse as the intracellular procaryote Bdellovibrio species, the filamentous bacteria streptomycetes, the protozoans Tetrahymena and Trypanosoma spp., mollusks, insects, and others. In these organisms, Pn have been isolated as constituents of glycolipids, glycoproteins, polysaccharides, or phosphonolipids. In Bacteroides fragilis, Pn were identified as components of capsular polysaccharide (6); in streptomycetes, Pn are synthesized as antibiotics such as fosfomycin (25); in Tetrahymena spp., Pn exist as phosphonolipids (19); in Trypanosoma cruzi, Pn are components of lipopeptidophosphoglycan (the major cell surface glycoconjugate [10]); in a sea anemone, Pn are the major P compounds (38); and in a locus, a Pn is the principal P compound of hemolymph (20). Yet, in spite of their widespread natural occurrence, the biological role of natural Pn is poorly understood (17). In phosphonolipids, 2-aminoethylphosphonate (AEPn) exists in place of its analog ethanolamine phosphate.No doubt because of the abundance of PN in nature, bacteria have acquired pathways for Pn breakdown. Bacteria capable of breaking the C-P bond may use Pn as a sole P source, for which two pathways exist, the C-P l...

show abstract

“…Although it is true that inorganic phosphate (P valence ϩ5) is the principal form of phosphorus in living systems and that phosphate-esters play a critical role in phosphate biochemistry, it is now clear that reduced phosphorus compounds of both natural and xenobiotic origin play important roles in numerous biological systems. Accordingly, many organisms have been shown to possess metabolic pathways for reduction of phosphate to a variety of reduced phosphorus compounds (1)(2)(3); others have been shown to possess metabolic pathways for oxidation of reduced phosphorus compounds (4 -9). Among the most striking of these is a recently isolated sulfate-reducing bacterium that obtains all of the energy it requires for growth from the oxidation of phosphite (ϩ3 valence) to phosphate (10).…”

mentioning

confidence: 99%

Purification and Characterization of a Novel Phosphorus-oxidizing Enzyme from Pseudomonas stutzeri WM88

Costas¹,

White²,

Metcalf

2001

Journal of Biological Chemistry

154

155

View full text Add to dashboard Cite

The ptxD gene from Pseudomonas stutzeri WM88 encoding the novel phosphorus oxidizing enzyme NAD:phosphite oxidoreductase (trivial name phosphite dehydrogenase, PtxD) was cloned into an expression vector and overproduced in Escherichia coli. The heterologously produced enzyme is indistinguishable from the native enzyme based on mass spectrometry, amino-terminal sequencing, and specific activity analyses. Recombinant PtxD was purified to homogeneity via a two-step affinity protocol and characterized. The enzyme stoichiometrically produces NADH and phosphate from NAD and phosphite. The reverse reaction was not observed. Gel filtration analysis of the purified protein is consistent with PtxD acting as a homodimer. PtxD has a high affinity for its substrates with K m values of 53.1 ؎ 6.7 M and 54.6 ؎ 6.7 M, for phosphite and NAD, respectively. V max and k cat were determined to be 12.2 ؎ 0.3 mol min ؊1 mg ؊1 and 440 min ؊1. NADP can substitute poorly for NAD; however, none of the numerous compounds examined were able to substitute for phosphite. Initial rate studies in the absence or presence of products and in the presence of the dead end inhibitor sulfite are most consistent with a sequential ordered mechanism for the PtxD reaction, with NAD binding first and NADH being released last. Amino acid sequence comparisons place PtxD as a new member of the D-2-hydroxyacid NAD-dependent dehydrogenases, the only one to have an inorganic substrate. To our knowledge, this is the first detailed biochemical study on an enzyme capable of direct oxidation of a reduced phosphorus compound.Phosphorus is widely reported to be a redox conservative element in biological systems, with the sum total of phosphorus biochemistry consisting of the formation and hydrolysis of phosphate-ester bonds. These reports imply that reduced phosphorus compounds are not important in living systems and that enzymatically catalyzed redox reactions of phosphorus compounds do not occur; however, an increasing body of evidence indicates that this is not the case. Although it is true that inorganic phosphate (P valence ϩ5) is the principal form of phosphorus in living systems and that phosphate-esters play a critical role in phosphate biochemistry, it is now clear that reduced phosphorus compounds of both natural and xenobiotic origin play important roles in numerous biological systems. Accordingly, many organisms have been shown to possess metabolic pathways for reduction of phosphate to a variety of reduced phosphorus compounds (1-3); others have been shown to possess metabolic pathways for oxidation of reduced phosphorus compounds (4 -9). Among the most striking of these is a recently isolated sulfate-reducing bacterium that obtains all of the energy it requires for growth from the oxidation of phosphite (ϩ3 valence) to phosphate (10).Unfortunately, detailed studies examining the mechanisms of biological phosphorus oxidation and reduction are scarce. This is particularly true with regard to the biochemical characterization of enzymes involved in reduced p...

show abstract

Phosphonolipids: Localization in Surface Membranes of Tetrahymena

Cited by 74 publications

References 10 publications

Bacterial carbon-phosphorus lyase: products, rates, and regulation of phosphonic and phosphinic acid metabolism

Bacterial carbon-phosphorus lyase: products, rates, and regulation of phosphonic and phosphinic acid metabolism

Molecular cloning, mapping, and regulation of Pho regulon genes for phosphonate breakdown by the phosphonatase pathway of Salmonella typhimurium LT2

Purification and Characterization of a Novel Phosphorus-oxidizing Enzyme from Pseudomonas stutzeri WM88

Contact Info

Product

Resources

About