Rearrangement reactions in the biosynthesis of molybdopterin--an NMR study with multiply 13C/15N labelled precursors.
The genes moaABC of Escherichia coli were ligated into the expression vector pNCO113. The resulting plasmid was transformed into a moeA mutant of E. coli. From cultures of the recombinant strain, a pteridine designated compound Z could be isolated at 5 mg/liter. Compound Z is a product of precursor Z, a biosynthetic precursor of molybdopterin. Cultures of the recombinant E. coli strain were supplied with [U-(13)C6]glucose, [U-(13)C5]ribulose 5-phosphate, or [7-(15)N,8-(13)C]guanine. The culture medium also contained a large excess of unlabeled glucose. Compound Z as well as nucleosides obtained by hydrolysis of RNA were isolated from the bacterial cultures, and their heavy isotope distribution was investigated by one-dimensional and two-dimensional NMR spectroscopy. The labelling patterns of compound Z show that the carbon atoms of a pentose or pentulose are diverted to the ring atoms C6 and C7 and to the side chain atoms C2', C3' and C4' of compound Z. Carbon atom C1' of compound Z is derived from carbon atom C8 of a guanine derivative. The remodeling of the carbon skeleton of the pentose and purine moieties proceed via intramolecular rearrangement reactions.
Institut für Organische Chemie und Biochemie, Technische Universität München, Garching, Germany.
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C
Rieder
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Eisenreich
J
J
O'Brien
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Richter
E
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Götze
P
P
Boyle
S
S
Blanchard
A
A
Bacher
H
H
Simon
D002247:Carbon Isotopes; D003067:Coenzymes / Q000096:biosynthesis*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins; D005947:Glucose / Q000378:metabolism; D006147:Guanine / Q000031:analogs & derivatives* / Q000378:metabolism; D007553:Isotope Labeling; D008667:Metalloproteins / Q000378:metabolism*; D008956:Models, Chemical; D008982:Molybdenum / Q000378:metabolism*; D000090006:Molybdenum Cofactors; D009154:Mutation; D009587:Nitrogen Isotopes; D019906:Nuclear Magnetic Resonance, Biomolecular; D011621:Pteridines / Q000378:metabolism*; D012274:Ribulosephosphates / Q000378:metabolism; D013466:Sulfurtransferases / Q000235:genetics
D002247:Carbon Isotopes; D003067:Coenzymes; D029968:Escherichia coli Proteins; D005947:Glucose; D006147:Guanine; D008667:Metalloproteins; D008982:Molybdenum; D000090006:Molybdenum Cofactors; D009587:Nitrogen Isotopes; D011621:Pteridines; D012274:Ribulosephosphates; D013466:Sulfurtransferases; C031524:ribulose 5-phosphate; C022261:molybdopterin; C111302:MoeA protein, E coli