Skip to main content
construction release_alert
Scholars@Duke will be undergoing maintenance April 11-15. Some features may be unavailable during this time.
cancel

Mechanistic and mutational studies of Escherichia coli molybdopterin synthase clarify the final step of molybdopterin biosynthesis.

Publication ,  Journal Article
Wuebbens, MM; Rajagopalan, KV
Published in: J Biol Chem
April 18, 2003

Biosynthesis of the molybdenum cofactor, a chelate of molybdenum or tungsten with a novel pterin, occurs in virtually all organisms including humans. In the cofactor, the metal is complexed to the unique cis-dithiolene moiety located on the pyran ring of molybdopterin. Escherichia coli molybdopterin synthase, the protein responsible for adding the dithiolene to a desulfo precursor termed precursor Z, is a dimer of dimers containing the MoaD and MoaE proteins. The sulfur used for dithiolene formation is carried in the form of a thiocarboxylate at the MoaD C terminus. Using an intein expression system for preparation of thiocarboxylated MoaD, the mechanism of the molybdopterin synthase reaction was examined. A stoichiometry of 2 molecules of thiocarboxylated MoaD per conversion of a single precursor Z molecule to molybdopterin was observed. Examination of several synthase variants bearing mutations in the MoaE subunit identified Lys-119 as a residue essential for activity and Arg-39 and Lys-126 as other residues critical for the reaction. An intermediate of the synthase reaction was identified and characterized. This intermediate remains tightly associated with the protein and is the predominant product formed by synthase containing the K126A variant of MoaE. Mass spectral data obtained from protein-bound intermediate are consistent with a monosulfurated structure that contains a terminal phosphate group similar to that present in molybdopterin.

Duke Scholars

Altmetric Attention Stats
Dimensions Citation Stats

Published In

J Biol Chem

DOI

ISSN

0021-9258

Publication Date

April 18, 2003

Volume

278

Issue

16

Start / End Page

14523 / 14532

Location

United States

Related Subject Headings

  • Time Factors
  • Sulfurtransferases
  • Pteridines
  • Molybdenum Cofactors
  • Models, Molecular
  • Models, Chemical
  • Metalloproteins
  • Mass Spectrometry
  • Ions
  • Genetic Vectors
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Wuebbens, M. M., & Rajagopalan, K. V. (2003). Mechanistic and mutational studies of Escherichia coli molybdopterin synthase clarify the final step of molybdopterin biosynthesis. J Biol Chem, 278(16), 14523–14532. https://doi.org/10.1074/jbc.M300453200
Wuebbens, Margot M., and K. V. Rajagopalan. “Mechanistic and mutational studies of Escherichia coli molybdopterin synthase clarify the final step of molybdopterin biosynthesis.J Biol Chem 278, no. 16 (April 18, 2003): 14523–32. https://doi.org/10.1074/jbc.M300453200.
Wuebbens, Margot M., and K. V. Rajagopalan. “Mechanistic and mutational studies of Escherichia coli molybdopterin synthase clarify the final step of molybdopterin biosynthesis.J Biol Chem, vol. 278, no. 16, Apr. 2003, pp. 14523–32. Pubmed, doi:10.1074/jbc.M300453200.

Published In

J Biol Chem

DOI

ISSN

0021-9258

Publication Date

April 18, 2003

Volume

278

Issue

16

Start / End Page

14523 / 14532

Location

United States

Related Subject Headings

  • Time Factors
  • Sulfurtransferases
  • Pteridines
  • Molybdenum Cofactors
  • Models, Molecular
  • Models, Chemical
  • Metalloproteins
  • Mass Spectrometry
  • Ions
  • Genetic Vectors