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Role of His residues in Bacillus subtilis cytochrome b558 for haem binding and assembly of succinate:quinone oxidoreductase (complex II)

Fridén, H and Hederstedt, Lars LU (1990) In Molecular Microbiology 4(6). p.1045-1056
Abstract
Cytochrome 5558 in the cytoplasmic membrane of
Bacilius subtiiis constitutes the anchor and electron
acceptor to the flavoprotein (Fp) and iron-sulphur
protein (Ip) in succinate:quinone oxidoreductase, and
seemingly contains two haem groups. EPR and MCD
spectroscopic data indicate bis-imidazole ligation of
the haem. Apo-cytochrome was found in the mem-
brane fraction of haem-deficient B. subtilis, suggest-
ing that during biogenesis of the oxidoreductase the
cytochrome b558 polypeptide is embedded into the
membrane prior to the incorporation of haem and
subsequent binding of Fp and Ip. The six His residues
in cytochrome b558 were individually changed to Tyr
to attempt identification of... (More)
Cytochrome 5558 in the cytoplasmic membrane of
Bacilius subtiiis constitutes the anchor and electron
acceptor to the flavoprotein (Fp) and iron-sulphur
protein (Ip) in succinate:quinone oxidoreductase, and
seemingly contains two haem groups. EPR and MCD
spectroscopic data indicate bis-imidazole ligation of
the haem. Apo-cytochrome was found in the mem-
brane fraction of haem-deficient B. subtilis, suggest-
ing that during biogenesis of the oxidoreductase the
cytochrome b558 polypeptide is embedded into the
membrane prior to the incorporation of haem and
subsequent binding of Fp and Ip. The six His residues
in cytochrome b558 were individually changed to Tyr
to attempt identification of residues serving as haem
axial ligands and to analyse the role of His residues for
assembly and function of the oxidoreductase. From
the properties of the mutants, His-47 can be excluded
as a haem ligand. The remaining His residues (at
positions 13,28,70,113
and
155) are located
in
or close
to four predicted transmembrane segments. The
Tyr-28 and Tyr-70 mutant proteins appeared to lack
one of the two haems. Only the Tyr-13 and Tyr-47
mutant cytochromes were found to function as
anchors for Fp and Ip, but the Tyr-13 mutant cyto-
chrome assembles into an enzymatically defective
succinate:quinone oxidoreductase. It is concluded
from a combination of the experimental findings,
sequence comparisons and membrane topology data
that His-28, His-70 and His-155 are probably haem
axial ligands in a dihaem cytochrome 6558. His-70 and
His-155 may be tigands to the same haem.
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Molecular Microbiology
volume
4
issue
6
pages
1045 - 1056
publisher
Wiley-Blackwell
ISSN
1365-2958
DOI
10.1111/j.1365-2958.1990.tb00677.x
language
English
LU publication?
yes
id
c1c30663-a5cd-437e-8175-fcb811a8e741
date added to LUP
2017-07-18 10:43:32
date last changed
2017-09-07 10:50:43
@article{c1c30663-a5cd-437e-8175-fcb811a8e741,
  abstract     = {Cytochrome 5558 in the cytoplasmic membrane of<br/>Bacilius subtiiis constitutes the anchor and electron<br/>acceptor to the flavoprotein (Fp) and iron-sulphur<br/>protein (Ip) in succinate:quinone oxidoreductase, and<br/>seemingly contains two haem groups. EPR and MCD<br/>spectroscopic data indicate bis-imidazole ligation of<br/>the haem. Apo-cytochrome was found in the mem-<br/>brane fraction of haem-deficient B. subtilis, suggest-<br/>ing that during biogenesis of the oxidoreductase the<br/>cytochrome b558 polypeptide is embedded into the<br/>membrane prior to the incorporation of haem and<br/>subsequent binding of Fp and Ip. The six His residues<br/>in cytochrome b558 were individually changed to Tyr<br/>to attempt identification of residues serving as haem<br/>axial ligands and to analyse the role of His residues for<br/>assembly and function of the oxidoreductase. From<br/>the properties of the mutants, His-47 can be excluded<br/>as a haem ligand. The remaining His residues (at<br/>positions 13,28,70,113<br/> and<br/> 155) are located<br/> in<br/> or close<br/>to four predicted transmembrane segments. The<br/>Tyr-28 and Tyr-70 mutant proteins appeared to lack<br/>one of the two haems. Only the Tyr-13 and Tyr-47<br/>mutant cytochromes were found to function as<br/>anchors for Fp and Ip, but the Tyr-13 mutant cyto-<br/>chrome assembles into an enzymatically defective<br/>succinate:quinone oxidoreductase. It is concluded<br/>from a combination of the experimental findings,<br/>sequence comparisons and membrane topology data<br/>that His-28, His-70 and His-155 are probably haem<br/>axial ligands in a dihaem cytochrome 6558. His-70 and<br/>His-155 may be tigands to the same haem.<br/>},
  author       = {Fridén, H and Hederstedt, Lars},
  issn         = {1365-2958},
  language     = {eng},
  number       = {6},
  pages        = {1045--1056},
  publisher    = {Wiley-Blackwell},
  series       = {Molecular Microbiology},
  title        = {Role of His residues in <em>Bacillus subtilis</em> cytochrome b558 for haem binding and assembly of succinate:quinone oxidoreductase (complex II)},
  url          = {http://dx.doi.org/10.1111/j.1365-2958.1990.tb00677.x },
  volume       = {4},
  year         = {1990},
}