Complex I in Escherichia coli
Home People Research

Analysis of primary amino acid sequence

Site-specific mutations in Complex I

Links

Complex I (also known as NDH-1) is the most complicated and the most challenging enzyme of respiratory chain. It consists of up to 46 subunits in eukaryotes, from 14 subunits in most bacterial species investigated to date, and "only" 13 subunits in E. coli. The enzyme contains as cofactors 1 FMN and up to nine FeS clusters, binuclear and tetranuclear . The enzyme operates as a proton pump, i.e. it catalyses the transfer of protons across the membrane coupled with transfer of electrons from NADH to ubi- or menaquinone.

The scheme is based on literature data and partially resolved structure of Complex I from T. thermophilus (PDB entry 3M9S). Known locations of redox centers within subunits are indicated. Several subunits have been suggested to house quinone binding sites.

 

In contrast to some other proton pumps (ATPsynthase, rhodopsin, terminal oxidases) the mechanism of proton transfer in Complex I remains completely enigmatic.
 

By using the structurally simpler and genetically modifiable Complex I from Escherichia coli, our goal is to elucidate the reaction mechanism of the proton pump

 

A graduate student position is available now in the Helsinki Bioenergetics Group, Programme for Structural Biology and Biophysics, Institute of Biotechnology, University of Helsinki 

There are possibilities to try your hand in biochemistry and biophysical studies relating to Complex I
Please contact Marina Verkhovskaya  for more details. Tel: 191 59 749 or 191 59 748

Publications

 
Verkhovskaya M, Knuuti, J., Wikström M.  (2010) Role of Ca2+ in structure and function of Complex I 
from Escherichia coli, Biochim. Biophys. Acta 1807, 36-41.
 
Euro L., Belevich G., Wikström M. and Verkhovskaya M. (2009) 
High affinity cation-binding sites in Complex I from Escherichia coli.
Biochim Biophys Acta 1787, 1024-1028.
 
Belevich N., Verkhovskaya M., Verkhovsky M.I. (2009) 
Chapter 4 Electron transfer in respiratory complexes resolved by an ultra-fast freeze-quench approach.
Methods Enzymol. 456, 75-93.
 
Euro L., Belevich G., Bloch D.,Verkhovsky M.I., Wikström M., Verkhovskaya M.  (2009) 
The role of the invariant glutamate 95 in the catalytic site of Complex I from Escherichia coli,
Biochim Biophys Acta 1787, 68-73
 
Euro L., Belevich G., Verkhovsky M.I., Wikström M., Verkhovskaya M.  (2008) 
Conserved lysine residues of the membrane subunit NuoM are involved in energy conversion by 
the proton-pumping NADH:ubiquinone oxidoreductase (Complex I), Biochim Biophys Acta 1777, 1166-72
 
Euro L., Bloch D.A., Wikström M., Verkhovsky M.I., Verkhovskaya M.  (2008) 
Electrostatic interactions between FeS clusters in NADH:ubiquinone oxidoreductase (Complex I)
from Escherichia coli, Biochemistry 47, 3185-93
 
Verkhovskaya M.L., Belevich N., Euro L., Wikström M., Verkhovsky M.I. (2008) 
Real-time electron transfer in respiratory complex I, Proc. Natl. Acad. Sci U. S. A 105, 3763-7
 
Belevich G., Euro L., Wikström M., and Verkhovskaya M. (2007) Role of the conserved 
arginine 274 and histidine 224 and 228 residues in the NuoCD subunit of complex I from Escherichia coli, 
Biochemistry 46, 526-33
 
Sinegina L., Wikström M., Verkhovsky M.I. and Verkhovskaya M. (2005) Activation of  isolated 
NADH:ubiquinone oxidoreductase I  (Complex I) from Escherichia coli by detergent and phospholipids. 
Recovery of ubiquinone reductase activity and changes in EPR signals of iron-sulfur clusters. Biochemistry 
44, 8500-8506