Biosynthesis of phosphonic acids in tetrahymena

Warren, William

doi:10.1016/0304-4165(68)90263-8

Cited by 63 publications

(28 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…It was proposed that phosphoenolpyruvate (PEP) was the most likely precursor of AEP, the initial biosynthetic step being an intramolecular rearrangement to yield 2-keto-3-phosphonopropionic acid. Subsequent studies with cell-free extracts of T. pyriformis (11,32) supported a reaction sequence involving, first, the rearrangement of PEP, followed by decarboxylation to yield phosphonoacetaldehyde which is then aminated to give AEP.…”

Section: \0mentioning

confidence: 98%

Biosynthesis of Fosfomycin by Streptomyces fradiae

Rogers

Birnbaum

1974

Antimicrob Agents Chemother

View full text Add to dashboard Cite

The antibiotic fosfomycin was produced as a secondary metabolite in a glucose-asparagine medium containing citrate, l -methionine, and l -glutamate. The citrate requirement for antibiotic synthesis was related to its requirement for growth. In contrast, l -methionine and l -glutamate caused a marked stimulation of fosfomycin production and had no effect on growth. l -Methionine had to be added early to effect maximal antibiotic synthesis later in the fermentation. The l -glutamate requirement was not specific, since several tricarboxylic acid cycle intermediates could replace this amino acid. l -Asparagine was the most effective nitrogen source for growth and production of fosfomycin. Glycine, an alternate nitrogen source, supported fosfomycin synthesis only when added in excess of that needed for growth. Cobalt and inorganic phosphate were required also for antibiotic production at concentrations exceeding those supporting maximal growth. Radioactive incorporation studies showed that the methyl carbon of methionine was the precursor of the methyl of fosfomycin. Carbon 1 of fosfomycin was derived from glucose carbons 1 and 6, whereas glucose- 2 - 14 C labeled fosfomycin carbon 2. Radioactivity from acetate- 2 - 14 C was distributed equally between fosfomycin carbons 1 and 2. No incorporation of acetate- 1 - 14 C , asparagine- U - 14 C , citrate- 1,5 - 14 C , or glutamate- U - 14 C occurred. The labeling pattern of fosfomycin carbons 1 and 2 was similar to that found in 2-aminoethylphosphonate from Tetrahymena .

show abstract

Section: \0mentioning

confidence: 98%

Biosynthesis of Fosfomycin by Streptomyces fradiae

Rogers

Birnbaum

1974

Antimicrob Agents Chemother

View full text Add to dashboard Cite

show abstract

“…1 (6,24,36). Because of its natural abundance and resistance to acid-, base-, and phosphotransferase-catalyzed hydrolysis (16), soil-dwelling bacteria have acquired a unique pathway for the degradation of AEP to usable forms of carbon, nitrogen, and phosphorus ( Fig.…”

mentioning

confidence: 99%

The 2-Aminoethylphosphonate-Specific Transaminase of the 2-Aminoethylphosphonate Degradation Pathway

et al. 2002

View full text Add to dashboard Cite

The 2-aminoethylphosphonate transaminase (AEPT; the phnW gene product) of the Salmonella enterica serovar Typhimurium 2-aminoethylphosphonate (AEP) degradation pathway catalyzes the reversible reaction of AEP and pyruvate to form phosphonoacetaldehyde (P-Ald) and L-alanine (L-Ala). Here, we describe the purification and characterization of recombinant AEPT. pH rate profiles (log V m and log V m /K m versus pH) revealed a pH optimum of 8.5. At pH 8.5, K eq is equal to 0.5 and the k cat values of the forward and reverse reactions are 7 and 9 s ؊1 , respectively. The K m for AEP is 1.11 ؎ 0.03 mM; for pyruvate it is 0.15 ؎ 0.02 mM, for P-Ald it is 0.09 ؎ 0.01 mM, and for L-Ala it is 1.4 ؎ 0.03 mM. Substrate specificity tests revealed a high degree of discrimination, indicating a singular physiological role for the transaminase in AEP degradation. The 40-kDa subunit of the homodimeric enzyme is homologous to other members of the pyridoxalphosphatedependent amino acid transaminase superfamily. Catalytic residues conserved within well-characterized members are also conserved within the seven known AEPT sequences. Site-directed mutagenesis demonstrated the importance of three selected residues (Asp168, Lys194, and Arg340) in AEPT catalysis.

show abstract

“…Extensive studies on their unique C-P bond formation mechanisms (1,8, 9,20,23,24) indicated that the first step of the C-P bond formation pathway is the intramolecular rearrangement of phosphoenolpyruvate (PEP) to phosphonopyruvate (PnPy) and that the equilibrium of this reaction heavily favors the formation of the phosphate ester ( Fig.…”

mentioning

confidence: 99%

Purification and characterization of phosphoenolpyruvate phosphomutase from Pseudomonas gladioli B-1

et al. 1992

View full text Add to dashboard Cite

Phosphoenolpyruvate phosphomutv-'^(PEPPM) catalyzes C-P bond formation by intramolecular rearrangement of phosphoenolpyruvate to pr fhonopyruvate (PnPy). We purified PEPPM from a gram-negative bacterium, Pseudomonas gladioli B isolated as a C-P compound producer. The equilibrium of this reaction favors the formation of the phosphate ester by deaving the C-P bond of PnPy, but the C-P bond-forming reaction is physiologically significant. The C-P bond-forming activity of PEPPM was confirmed with a purified protein. The molecular mass of the native enzyme was estimated to be 263 and 220 kDa by gel filtration and polyacrylamide gel electrophoresis, respectively. A subunit molecular mass of 61 kDa was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that the native protein was a tetramer.The optimum pH and temperature were 7.5 to 8.0 and 40°C, respectively. The K. value for PnPy was 19 ± 3.5 ,M, and the maximum initial velocity of the conversion of PnPy to phosphoenolpyruvate was 200 ,uM/s/mg. PEPPM was activated by the presence of the divalent metal ion, and the K. values were 3.5 ± 1.4 FM for Mge+, 16 + 5 nM for Mn+, 3.0 ± 1.5 PM for Zn2+, and 1.2 ± 0.2 P1M for Co2+.Since the discovery of the first natural C-P compound, 2-aminoethylphosphonic acid (10), various metabolites with C-P bonds have been isolated and the presence of phosphonates and phosphinates in a variety of biological systems has been established. Extensive studies on their unique C-P bond formation mechanisms (1,8, 9,20,23,24) indicated that the first step of the C-P bond formation pathway is the intramolecular rearrangement of phosphoenolpyruvate (PEP) to phosphonopyruvate (PnPy) and that the equilibrium of this reaction heavily favors the formation of the phosphate ester ( Fig.

show abstract

Biosynthesis of phosphonic acids in tetrahymena

Cited by 63 publications

References 27 publications

Biosynthesis of Fosfomycin by Streptomyces fradiae

Biosynthesis of Fosfomycin by Streptomyces fradiae

The 2-Aminoethylphosphonate-Specific Transaminase of the 2-Aminoethylphosphonate Degradation Pathway

Purification and characterization of phosphoenolpyruvate phosphomutase from Pseudomonas gladioli B-1

Contact Info

Product

Resources

About