Gene Symbol: mob
Description: molybdopterin-guanine dinucleotide synthase
Alias: ECK3849, JW3829, chlB, mob, narB
Species: Escherichia coli str. K-12 substr. MG1655

Top Publications

  1. Reschke S, Sigfridsson K, Kaufmann P, Leidel N, Horn S, Gast K, et al. Identification of a bis-molybdopterin intermediate in molybdenum cofactor biosynthesis in Escherichia coli. J Biol Chem. 2013;288:29736-45 pubmed publisher
  2. Santini C, Iobbi Nivol C, Romane C, Boxer D, Giordano G. Molybdoenzyme biosynthesis in Escherichia coli: in vitro activation of purified nitrate reductase from a chlB mutant. J Bacteriol. 1992;174:7934-40 pubmed
    All molybdoenzyme activities are absent in chlB mutants because of their inability to synthesize molybdopterin guanine dinucleotide, which together with molybdate constitutes the molybdenum cofactor in Escherichia coli...
  3. Vergnes A, Gouffi Belhabich K, Blasco F, Giordano G, Magalon A. Involvement of the molybdenum cofactor biosynthetic machinery in the maturation of the Escherichia coli nitrate reductase A. J Biol Chem. 2004;279:41398-403 pubmed
  4. Magalon A, Frixon C, Pommier J, Giordano G, Blasco F. In vivo interactions between gene products involved in the final stages of molybdenum cofactor biosynthesis in Escherichia coli. J Biol Chem. 2002;277:48199-204 pubmed
    ..These results suggest that, in vivo, molybdenum cofactor biosynthesis occurs on protein complexes rather than by the separate action of molybdenum cofactor biosynthetic proteins. ..
  5. Boxer D, Low D, Pommier J, Giordano G. Involvement of a low-molecular-weight substance in in vitro activation of the molybdoenzyme respiratory nitrate reductase from a chlB mutant of Escherichia coli. J Bacteriol. 1987;169:4678-85 pubmed
    The soluble subcellular fraction of a chlB mutant contains an inactive precursor form of the molybdoenzyme nitrate reductase, which can be activated by the addition to the soluble fraction of protein FA, which is thought to be the active ..
  6. Johnson J, Indermaur L, Rajagopalan K. Molybdenum cofactor biosynthesis in Escherichia coli. Requirement of the chlB gene product for the formation of molybdopterin guanine dinucleotide. J Biol Chem. 1991;266:12140-5 pubmed
    ..In this paper, we have examined the biochemistry of the chlB mutant and show that the gene product of the chlB locus is essential for the addition of the GMP moiety to form ..
  7. Casse F. Mapping of the gene chl-B controlling membran bound nitrate reductase and formic hydrogen-lyase activities in Escherichia coli K 12. Biochem Biophys Res Commun. 1970;39:429-36 pubmed
  8. Lake M, Temple C, Rajagopalan K, Schindelin H. The crystal structure of the Escherichia coli MobA protein provides insight into molybdopterin guanine dinucleotide biosynthesis. J Biol Chem. 2000;275:40211-7 pubmed
    ..The binding site for MPT is located adjacent to the GTP-binding site in the C-terminal half of the molecule, which contains another set of conserved residues presumably involved in MPT binding. ..
  9. Palmer T, Vasishta A, Whitty P, Boxer D. Isolation of protein FA, a product of the mob locus required for molybdenum cofactor biosynthesis in Escherichia coli. Eur J Biochem. 1994;222:687-92 pubmed
    The mob mutants in Escherichia coli are pleiotropically defective in all molybdoenzyme activities...

More Information


  1. Reiss J, Kleinhofs A, Klingm├╝ller W. Cloning of seven differently complementing DNA fragments with chl functions from Escherichia coli K12. Mol Gen Genet. 1987;206:352-5 pubmed
    ..The established complementation groups plus mutants of the chlD type represent eight distinct functions, which are all believed to be required for the molybdenum cofactor activity in the reduction of nitrate to nitrite by E. coli. ..
  2. Bachmann B. Linkage map of Escherichia coli K-12, edition 7. Microbiol Rev. 1983;47:180-230 pubmed
  3. Iobbi Nivol C, Palmer T, Whitty P, McNairn E, Boxer D. The mob locus of Escherichia coli K12 required for molybdenum cofactor biosynthesis is expressed at very low levels. Microbiology. 1995;141 ( Pt 7):1663-71 pubmed
    The mob locus of Escherichia coli encodes functions which catalyse the synthesis of active molybdenum cofactor, molybdopterin guanine dinucleotide, from molybdopterin and GTP...
  4. del Campillo Campbell A, Campbell A. Molybdenum cofactor requirement for biotin sulfoxide reduction in Escherichia coli. J Bacteriol. 1982;149:469-78 pubmed
    ..The products of four other E. coli genes (chlA, chlB, chlE and chlG) are also needed for enzymatic activity...
  5. Palmer T, Santini C, Iobbi Nivol C, Eaves D, Boxer D, Giordano G. Involvement of the narJ and mob gene products in distinct steps in the biosynthesis of the molybdoenzyme nitrate reductase in Escherichia coli. Mol Microbiol. 1996;20:875-84 pubmed
    The Escherichia coli mob locus is required for synthesis of active molybdenum cofactor, molybdopterin guanine dinucleotide...
  6. Adhya S, Cleary P, Campbell A. A deletion analysis of prophage lambda and adjacent genetic regions. Proc Natl Acad Sci U S A. 1968;61:956-62 pubmed
  7. Rothery R, Grant J, Johnson J, Rajagopalan K, Weiner J. Association of molybdopterin guanine dinucleotide with Escherichia coli dimethyl sulfoxide reductase: effect of tungstate and a mob mutation. J Bacteriol. 1995;177:2057-63 pubmed
    ..DmsABC) to be molybdopterin (MPT) guanine dinucleotide (MGD) and have studied the effects of tungstate and a mob mutation on cofactor (Mo-MGD) insertion. Tungstate severely inhibits anaerobic growth of E...
  8. Rothery R, Magalon A, Giordano G, Guigliarelli B, Blasco F, Weiner J. The molybdenum cofactor of Escherichia coli nitrate reductase A (NarGHI). Effect of a mobAB mutation and interactions with [Fe-S] clusters. J Biol Chem. 1998;273:7462-9 pubmed
    ..0 of the highest potential [4Fe-4S] cluster. ..
  9. Guse A, Stevenson C, Kuper J, Buchanan G, Schwarz G, Giordano G, et al. Biochemical and structural analysis of the molybdenum cofactor biosynthesis protein MobA. J Biol Chem. 2003;278:25302-7 pubmed
    ..Surprisingly, the individual and double substitution of asparagines 180 and 182 to aspartate did not affect MPT binding, catalysis, and product stabilization. ..
  10. Shanmugam K, Stewart V, Gunsalus R, Boxer D, Cole J, Chippaux M, et al. Proposed nomenclature for the genes involved in molybdenum metabolism in Escherichia coli and Salmonella typhimurium. Mol Microbiol. 1992;6:3452-4 pubmed
  11. Glaser J, DeMoss J. Comparison of nitrate reductase mutants of Escherichia coli selected by alternative procedures. Mol Gen Genet. 1972;116:1-10 pubmed
  12. Fimmel A, Haddock B. Use of chlC-lac fusions to determine regulation of gene chlC in Escherichia coli K-12. J Bacteriol. 1979;138:726-30 pubmed
    ..Gene fusions between the lac structural genes and the chlC locus were isolated, and the regulation of lac gene expression was studied. The fused lac genes were induced by nitrate anaerobically and repressed by the presence of oxygen. ..
  13. Rajagopalan K. Biosynthesis and processing of the molybdenum cofactors. Biochem Soc Trans. 1997;25:757-61 pubmed
  14. Neumann M, Seduk F, Iobbi Nivol C, Leimkuhler S. Molybdopterin dinucleotide biosynthesis in Escherichia coli: identification of amino acid residues of molybdopterin dinucleotide transferases that determine specificity for binding of guanine or cytosine nucleotides. J Biol Chem. 2011;286:1400-8 pubmed publisher
    ..Analysis of protein-protein interactions showed that the C-terminal domain of either MocA or MobA determines the specific binding to the respective acceptor protein. ..
  15. Lambdren P, Guest J. A novel method for isolating chlorate-resistant mutants of Escherichia coli K12 by anaerobic selection on a lactate plus fumarate medium. J Gen Microbiol. 1976;93:173-6 pubmed