Methenyl-tetrahydromethanopterin cyclohydrolase in cell extracts of Methanobacterium.

@article{Donnelly1985MethenyltetrahydromethanopterinCI,
  title={Methenyl-tetrahydromethanopterin cyclohydrolase in cell extracts of Methanobacterium.},
  author={Mark I. Donnelly and Jorge C. Escalante‐Semerena and Kenneth L. Jun. Rinehart and Ralph S. Wolfe},
  journal={Archives of biochemistry and biophysics},
  year={1985},
  volume={242 2},
  pages={
          430-9
        }
}
N5,N10-Methenyltetrahydromethanopterin cyclohydrolase from the extremely thermophilic sulfate reducing Archaeoglobus fulgidus: comparison of its properties with those of the cyclohydrolase from the extremely thermophilic Methanopyrus kandleri
TLDR
The purification and properties of the enzyme from A. fulgidus was purified 180-fold to apparent homogeneity and its properties were compared with those recently published for the cyclohydrolase from M. kandleri, which differed significantly with respect of the effect of K2HPO4 and of other salts on the activity and the stability.
Tetrahydrofolate-specific enzymes in Methanosarcina barkeri and growth dependence of this methanogenic archaeon on folic acid or p-aminobenzoic acid
TLDR
The results indicate that M. barkeri should contain H4F, which was supported by the finding that growth of M. barkingeri was dependent on folic acid and that the vitamin could be substituted by p-aminobenzoic acid, a biosynthetic precursor of H 4F.
Purification and properties of 5,10-methenyltetrahydromethanopterin cyclohydrolase from Methanosarcina barkeri
TLDR
The 5,10-methenyltetrahydromethanopterin cyclohydrolase from Methanosarcina barkeri was purified 313-fold to a specific activity of 470 mumol min-1 mg-1 at 37 degrees C and pH 7.8 and the monofunctional enzyme was oxygen stable, but the presence of a detergent proved to be essential for its stability.
Structures of the modified folates in the thermophilic archaebacteria Pyrococcus furiosus.
  • R. White
  • Chemistry, Biology
    Biochemistry
  • 1993
TLDR
The structures of the modified folates present in Pyrococcus furiosus have been determined and the characterization of the arylamines resulting from the air oxidative cleavage of the reduced modified folate present in these cells was accomplished, using both chemical and enzymatic methods.
Salt dependence, kinetic properties and catalytic mechanism of N-formylmethanofuran:tetrahydromethanopterin formyltransferase from the extreme thermophile Methanopyrus kandleri.
TLDR
Thermostability as well as activity of formyltransferase was dramatically increased in the presence of salts, 1.5 M being required for optimal stabilization and 1.2 M for half-maximal activity.
Structure and catalytic mechanism of N(5),N(10)-methenyl-tetrahydromethanopterin cyclohydrolase.
Methenyltetrahydromethanopterin (methenyl-H(4)MPT(+)) cyclohydrolase (Mch) catalyzes the interconversion of methenyl-H(4)MPT(+) and formyl-H(4)MPT in the one-carbon energy metabolism of methanogenic,
N5,N10-Methenyltetrahydromethanopterin cyclohydrolase from the extreme thermophile Methanopyrus kandleri: increase of catalytic efficiency (kcat/KM) and thermostability in the presence of salts
The activity of purified N5,N10-methenyltetrahydromethanopterin cyclohydrolase from Methanopyrus kandleri was found to increase up to 200-fold when potassium phosphate was added in high
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References

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Elucidation of the structure of methanopterin, a coenzyme from Methanobacterium thermoautotrophicum, using two-dimensional nuclear-magnetic-resonance techniques.
Methanopterin is a coenzyme involved in methanogenesis. From 2 kg wet cells of Methanobacterium thermoautotrophicum about 35 mumol methanopterin were isolated. The structure of this compound was
Formaldehyde oxidation and methanogenesis
TLDR
Formaldehyde oxidation by cell-free extracts of Methanobacterium thermoautotrophicum was shown to drive methanogenesis from CH3-S-coenzyme M or HCHO under a nonreductive atmosphere of N2, and an unidentified, oxygen-labile cofactor, the formaldehyde activation factor, present in boiled-cell extract was discovered.
Methanofuran (carbon dioxide reduction factor), a formyl carrier in methane production from carbon dioxide in Methanobacterium.
TLDR
Formylmethanofuran was enzymically converted to 14CH4 in the presence of CH3-S-CoM [2-(methylthio)ethanesulfonic acid], hydrogen, and methanopterin, establishing the formyl moiety as an intermediate in methanogenesis.
One-carbon metabolism in methanogenic bacteria: analysis of short-term fixation products of 14CO2 and 14CH3OH incorporated into whole cells
TLDR
The data indicated the absence of the Calvin, serine, and hexulose phosphate paths of C1 assimilation in the methanogens examined and indicated that pyruvate was an early intermediate product of net CO2 fixation, demonstrating the in vivo importance of coenzyme M derivatives in methanogenesis was demonstrated.
Structure and methylation of coenzyme M(HSCH2CH2SO3).
Derivatives of methanopterin, a coenzyme involved in methanogenesis.
TLDR
Methanosarcina barkeri contains a closely related coenzyme called sarcinapterin, which was identified as a L-glutamyl derivative of methanopterin, where the glutamate moiety is attached to thealpha-carboxylic acid group of the alpha-hydroxyglutaric acid moiety of methnopterin via an amide linkage.
The transmembrane electrical potential and intracellular pH in methanogenic bacteria.
TLDR
The magnitudes of the electrical potential and proton gradient in Methanospirillum hungatei GP1 and Methanobacterium thermoautotrophicum were determined and are interpreted in terms of proton efflux and monovalent cation antiport activities at the cytoplasmic membrane, with possible proton pumping at the site of internal vesicles.
Conformational studies on 5-formyl-5,6,7,8-tetrahydrofolic acid (folinic acid) using 1H and 13C nuclear magnetic resonance measurements: two interconverting conformations
The 1H and 13C n.m.r. spectra of the (±)-L-diastereoisomers of folinic acid have been recorded. No spectral differences between the two diastereoisomers were detected but a mixture of two slowly
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