JBIC Journal of Biological Inorganic Chemistry

, Volume 12, Issue 8, pp 1129–1139

Probing the role of copper in the biosynthesis of the molybdenum cofactor in Escherichia coli and Rhodobacter sphaeroides

  • M. Scott Morrison
  • Paul A. Cobine
  • Eric L. Hegg
Original Paper

DOI: 10.1007/s00775-007-0279-x

Cite this article as:
Morrison, M.S., Cobine, P.A. & Hegg, E.L. J Biol Inorg Chem (2007) 12: 1129. doi:10.1007/s00775-007-0279-x

Abstract

The crystal structure of Cnx1G, an enzyme involved in the biosynthesis of the molybdenum cofactor (Moco) in Arabidopsis thaliana, revealed the remarkable feature of a copper ion bound to the dithiolene unit of a molybdopterin intermediate (Kuper et al. Nature 430:803–806, 2004). To characterize further the role of copper in Moco biosynthesis, we examined the in vivo and/or in vitro activity of two Moco-dependent enzymes, dimethyl sulfoxide reductase (DMSOR) and nitrate reductase (NR), from cells grown under a variety of copper conditions. We found the activities of DMSOR and NR were not affected when copper was depleted from the media of either Escherichia coli or Rhodobacter sphaeroides. These data suggest that while copper may be utilized during Moco biosynthesis when it is available, copper does not appear to be strictly required for Moco biosynthesis in these two organisms.

Keywords

Molybdenum cofactorMolybdopterinDimethyl sulfoxide reductaseNitrate reductaseCopper

Abbreviations

BCS

Bathocuproine disulfonic acid

DMS

Dimethyl sulfide

DMSO

Dimethyl sulfoxide

DMSOR

Dimethyl sulfoxide reductase

GC

Gas chromatography

ICP

Inductively coupled plasma

LB

Luria–Bertani

MDH

Malate dehydrogenase

MGD

Molybdopterin guanine dinucleotide

Moco

Molybdenum cofactor

MPT

Molybdopterin

MPT-AMP

Adenylylated molybdopterin

NR

Nitrate reductase

WT

Wild-type

Supplementary material

Copyright information

© SBIC 2007

Authors and Affiliations

  • M. Scott Morrison
    • 1
  • Paul A. Cobine
    • 2
  • Eric L. Hegg
    • 3
  1. 1.Department of ChemistryUniversity of UtahSalt Lake CityUSA
  2. 2.Departments of Medicine and BiochemistryUniversity of Utah Health Science CenterSalt Lake CityUSA
  3. 3.Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingUSA