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The trinuclear iron-sulfur cluster S-3 in Bacillus subtilis succinate:menaquinone reductase; effects of a mutation in the putative cluster ligation motif on enzyme activity and EPR properties

Hägerhäll, Cecilia LU ; Sled, Vladimir D.; Hederstedt, Lars LU and Ohnishi, Tomoko (1995) In Biochimica et Biophysica Acta - Bioenergetics 1229(3). p.356-362
Abstract
Succinate:quinone reductases (SQRs) and quinol:fumarate reductases (QFRs) each contain a bi-, a tri- and a tetra-nuclear iron-sulfur cluster. The C-terminal half of the iron-sulfur protein subunit of these enzymes shows two fully conserved motifs of cysteine residues, stereotypical for ligands of [3Fe-4S] and [4Fe-4S] clusters. To analyze the functional role of the trinuclear cluster S3 in Bacillus subtilis SQR, a fourth cysteine residue was introduced into the putative ligation motif to that cluster. A corresponding mutation in Escherichia coli QFR results in a tri- to tetranuclear conversion (Manodori et al. (1992) Biochemistry 31, 2703–2731). We have found that presence of the extra cysteine in B. subtilis SQR does not result in cluster... (More)
Succinate:quinone reductases (SQRs) and quinol:fumarate reductases (QFRs) each contain a bi-, a tri- and a tetra-nuclear iron-sulfur cluster. The C-terminal half of the iron-sulfur protein subunit of these enzymes shows two fully conserved motifs of cysteine residues, stereotypical for ligands of [3Fe-4S] and [4Fe-4S] clusters. To analyze the functional role of the trinuclear cluster S3 in Bacillus subtilis SQR, a fourth cysteine residue was introduced into the putative ligation motif to that cluster. A corresponding mutation in Escherichia coli QFR results in a tri- to tetranuclear conversion (Manodori et al. (1992) Biochemistry 31, 2703–2731). We have found that presence of the extra cysteine in B. subtilis SQR does not result in cluster conversion. It does, however, affect the EPR properties of the cluster S3, whereas those of the other two clusters remain normal. The results strongly support the view that residues in the most C-terminal cysteine motif in the iron-sulfur protein subunit of SQRs and QFRs ligate the trinuclear cluster. Compared to wild-type SQR, S3 in the B. subtilis mutant enzyme is not sensitive to methanol and the midpoint redox potential is close to normal. The quinone reductase activity of the mutant enzyme is only 35% of normal. Thus, the architecture around cluster S3 plays a role in electron transfer to quinone or in the binding of quinone to the enzyme. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Site-directed mutagenesis, Iron-sulfur cluster, Bacillus subtilis
in
Biochimica et Biophysica Acta - Bioenergetics
volume
1229
issue
3
pages
356 - 362
publisher
Elsevier
external identifiers
  • scopus:0029002342
ISSN
0005-2728
DOI
10.1016/0005-2728(95)00023-C
language
English
LU publication?
yes
id
edaa800b-3ed1-49d0-ab05-7def6bb9a0a0
date added to LUP
2017-07-18 10:12:14
date last changed
2017-09-03 05:25:13
@article{edaa800b-3ed1-49d0-ab05-7def6bb9a0a0,
  abstract     = {Succinate:quinone reductases (SQRs) and quinol:fumarate reductases (QFRs) each contain a bi-, a tri- and a tetra-nuclear iron-sulfur cluster. The C-terminal half of the iron-sulfur protein subunit of these enzymes shows two fully conserved motifs of cysteine residues, stereotypical for ligands of [3Fe-4S] and [4Fe-4S] clusters. To analyze the functional role of the trinuclear cluster S3 in Bacillus subtilis SQR, a fourth cysteine residue was introduced into the putative ligation motif to that cluster. A corresponding mutation in Escherichia coli QFR results in a tri- to tetranuclear conversion (Manodori et al. (1992) Biochemistry 31, 2703–2731). We have found that presence of the extra cysteine in B. subtilis SQR does not result in cluster conversion. It does, however, affect the EPR properties of the cluster S3, whereas those of the other two clusters remain normal. The results strongly support the view that residues in the most C-terminal cysteine motif in the iron-sulfur protein subunit of SQRs and QFRs ligate the trinuclear cluster. Compared to wild-type SQR, S3 in the B. subtilis mutant enzyme is not sensitive to methanol and the midpoint redox potential is close to normal. The quinone reductase activity of the mutant enzyme is only 35% of normal. Thus, the architecture around cluster S3 plays a role in electron transfer to quinone or in the binding of quinone to the enzyme.},
  author       = {Hägerhäll, Cecilia and Sled, Vladimir D. and Hederstedt, Lars and Ohnishi, Tomoko},
  issn         = {0005-2728},
  keyword      = {Site-directed mutagenesis,Iron-sulfur cluster,Bacillus subtilis},
  language     = {eng},
  number       = {3},
  pages        = {356--362},
  publisher    = {Elsevier},
  series       = {Biochimica et Biophysica Acta - Bioenergetics},
  title        = {The trinuclear iron-sulfur cluster S-3 in <em>Bacillus subtilis</em> succinate:menaquinone reductase; effects of a mutation in the putative cluster ligation motif on enzyme activity and EPR properties},
  url          = {http://dx.doi.org/10.1016/0005-2728(95)00023-C},
  volume       = {1229},
  year         = {1995},
}