Structure of the molybdenum-cofactor biosynthesis protein MoaB of Escherichia coli

Acta Crystallogr D Biol Crystallogr. 2004 Jun;60(Pt 6):1068-75. doi: 10.1107/S0907444904007164. Epub 2004 May 21.


The moaABC operon of Escherichia coli is involved in early steps of the biosynthesis of the molybdenum-binding cofactor molybdopterin, but the precise functions of the cognate proteins are not known. The crystal structure of the MoaB protein from E. coli was determined by multiple anomalous dispersion at 2.1 angstroms A resolution and refined to an R factor of 20.4% (Rfree = 25.0%). The protein is a 32-symmetric hexamer, with the monomers consisting of a central beta-sheet flanked by helices on both sides. The overall fold of the monomer is similar to those of the MogA protein of E. coli, the G-domains of rat and human gephyrin and the G-domains of Cnx1 protein from A. thaliana, all of which are involved in the insertion of an unknown molybdenum species into molybdopterin to form the molybdenum cofactor. Furthermore, the MoaB protein shows significant sequence similarity to the cinnamon protein from Drosophila melanogaster. In addition to other functions, all these proteins are involved in the biosynthesis of the molybdenum cofactor and have been shown to bind molybdopterin. The close structural homology to MogA and the gephyrin and Cnx1 domains suggests that MoaB may bind a hitherto unidentified pterin compound, possibly an intermediate in molybdopterin biosynthesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Arabidopsis Proteins / chemistry
  • Binding Sites
  • Calnexin / chemistry
  • Carrier Proteins / chemistry
  • Cloning, Molecular
  • Crystallography, X-Ray
  • DNA / chemistry
  • Drosophila Proteins / chemistry
  • Drosophila melanogaster
  • Electrophoresis, Polyacrylamide Gel
  • Escherichia coli / metabolism*
  • Escherichia coli Proteins / chemistry*
  • Membrane Proteins / chemistry
  • Metalloproteins / chemistry
  • Methionine / chemistry
  • Models, Molecular
  • Molecular Sequence Data
  • Oligonucleotides / chemistry
  • Plasmids / metabolism
  • Polymerase Chain Reaction
  • Protein Conformation
  • Protein Folding
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Recombinant Proteins / chemistry
  • Selenomethionine / chemistry
  • Sequence Homology, Amino Acid


  • Arabidopsis Proteins
  • CNX1 protein, Arabidopsis
  • Carrier Proteins
  • Drosophila Proteins
  • Escherichia coli Proteins
  • Membrane Proteins
  • Metalloproteins
  • MoaB protein, E coli
  • Mog protein, E coli
  • Oligonucleotides
  • Recombinant Proteins
  • cin protein, Drosophila
  • gephyrin
  • Calnexin
  • DNA
  • Selenomethionine
  • Methionine