---
_id: '1980'
abstract:
- lang: eng
text: Non-proton pumping type II NADH dehydrogenase (NDH-2) plays a central role
in the respiratory metabolism of bacteria, and in the mitochondria of fungi, plants
and protists. The lack of NDH-2 in mammalian mitochondria and its essentiality
in important bacterial pathogens suggests these enzymes may represent a potential
new drug target to combat microbial pathogens. Here, we report the first crystal
structure of a bacterial NDH-2 enzyme at 2.5Å resolution from Caldalkalibacillus
thermarum. The NDH-2 structure reveals a homodimeric organization that has a unique
dimer interface. NDH-2 is localized to the cytoplasmic membrane by two separated
C-terminal membrane-anchoring regions that are essential for membrane localization
and FAD binding, but not NDH-2 dimerization. Comparison of bacterial NDH-2 with
the yeast NADH dehydrogenase (Ndi1) structure revealed non-overlapping binding
sites for quinone and NADH in the bacterial enzyme. The bacterial NDH-2 structure
establishes a framework for the structure-based design of small-molecule inhibitors.
acknowledgement: Funded by Health Research Council of New Zealand Royal Society
of New Zealand University of Otago New Zealand Synchrotron Group
author:
- first_name: Adam
full_name: 'Heikal, Adam '
last_name: Heikal
- first_name: Yoshio
full_name: Nakatani, Yoshio
last_name: Nakatani
- first_name: Elyse
full_name: Dunn, Elyse A
last_name: Dunn
- first_name: Marion
full_name: Weimar, Marion R
last_name: Weimar
- first_name: Catherine
full_name: Day, Catherine
last_name: Day
- first_name: Edward
full_name: Baker, Edward N
last_name: Baker
- first_name: Shaun
full_name: Lott, Shaun J
last_name: Lott
- first_name: Leonid A
full_name: Leonid Sazanov
id: 338D39FE-F248-11E8-B48F-1D18A9856A87
last_name: Sazanov
orcid: 0000-0002-0977-7989
- first_name: Gregory
full_name: Cook, Gregory
last_name: Cook
citation:
ama: 'Heikal A, Nakatani Y, Dunn E, et al. Structure of the bacterial type II NADH
dehydrogenase: a monotopic membrane protein with an essential role in energy generation.
Molecular Microbiology. 2014;91(5):950-964. doi:10.1111/mmi.12507'
apa: 'Heikal, A., Nakatani, Y., Dunn, E., Weimar, M., Day, C., Baker, E., … Cook,
G. (2014). Structure of the bacterial type II NADH dehydrogenase: a monotopic
membrane protein with an essential role in energy generation. Molecular Microbiology.
Wiley-Blackwell. https://doi.org/10.1111/mmi.12507'
chicago: 'Heikal, Adam, Yoshio Nakatani, Elyse Dunn, Marion Weimar, Catherine Day,
Edward Baker, Shaun Lott, Leonid A Sazanov, and Gregory Cook. “Structure of the
Bacterial Type II NADH Dehydrogenase: A Monotopic Membrane Protein with an Essential
Role in Energy Generation.” Molecular Microbiology. Wiley-Blackwell, 2014.
https://doi.org/10.1111/mmi.12507.'
ieee: 'A. Heikal et al., “Structure of the bacterial type II NADH dehydrogenase:
a monotopic membrane protein with an essential role in energy generation,” Molecular
Microbiology, vol. 91, no. 5. Wiley-Blackwell, pp. 950–964, 2014.'
ista: 'Heikal A, Nakatani Y, Dunn E, Weimar M, Day C, Baker E, Lott S, Sazanov LA,
Cook G. 2014. Structure of the bacterial type II NADH dehydrogenase: a monotopic
membrane protein with an essential role in energy generation. Molecular Microbiology.
91(5), 950–964.'
mla: 'Heikal, Adam, et al. “Structure of the Bacterial Type II NADH Dehydrogenase:
A Monotopic Membrane Protein with an Essential Role in Energy Generation.” Molecular
Microbiology, vol. 91, no. 5, Wiley-Blackwell, 2014, pp. 950–64, doi:10.1111/mmi.12507.'
short: A. Heikal, Y. Nakatani, E. Dunn, M. Weimar, C. Day, E. Baker, S. Lott, L.A.
Sazanov, G. Cook, Molecular Microbiology 91 (2014) 950–964.
date_created: 2018-12-11T11:55:01Z
date_published: 2014-03-01T00:00:00Z
date_updated: 2021-01-12T06:54:29Z
day: '01'
doi: 10.1111/mmi.12507
extern: 1
intvolume: ' 91'
issue: '5'
month: '03'
page: 950 - 964
publication: Molecular Microbiology
publication_status: published
publisher: Wiley-Blackwell
publist_id: '5103'
quality_controlled: 0
status: public
title: 'Structure of the bacterial type II NADH dehydrogenase: a monotopic membrane
protein with an essential role in energy generation'
type: journal_article
volume: 91
year: '2014'
...
---
_id: '1979'
abstract:
- lang: eng
text: NADH-ubiquinone oxidoreductase (complex I) is the first and largest enzyme
in the respiratory chain of mitochondria and many bacteria. It couples the transfer
of two electrons between NADH and ubiquinone to the translocation of four protons
across the membrane. Complex I is an L-shaped assembly formed by the hydrophilic
(peripheral) arm, containing all the redox centres performing electron transfer
and the membrane arm, containing proton-translocating machinery. Mitochondrial
complex I consists of 44 subunits of about 1 MDa in total, whilst the prokaryotic
enzyme is simpler and generally consists of 14 conserved “core” subunits. Recently
we have determined the first atomic structure of the entire complex I, using the
enzyme from Thermus thermophilus (536 kDa, 16 subunits, 9 Fe-S clusters, 64 TM
helices). Structure suggests a unique coupling mechanism, with redox energy of
electron transfer driving proton translocation via long-range (up to ~200 Å) conformational
changes. It resembles a steam engine, with coupling elements (akin to coupling
rods) linking parts of this molecular machine.
author:
- first_name: Leonid A
full_name: Leonid Sazanov
id: 338D39FE-F248-11E8-B48F-1D18A9856A87
last_name: Sazanov
orcid: 0000-0002-0977-7989
citation:
ama: Sazanov LA. The mechanism of coupling between electron transfer and proton
translocation in respiratory complex I. Journal of Bioenergetics and Biomembranes.
2014;46(4):247-253. doi:10.1007/s10863-014-9554-z
apa: Sazanov, L. A. (2014). The mechanism of coupling between electron transfer
and proton translocation in respiratory complex I. Journal of Bioenergetics
and Biomembranes. Springer. https://doi.org/10.1007/s10863-014-9554-z
chicago: Sazanov, Leonid A. “The Mechanism of Coupling between Electron Transfer
and Proton Translocation in Respiratory Complex I.” Journal of Bioenergetics
and Biomembranes. Springer, 2014. https://doi.org/10.1007/s10863-014-9554-z.
ieee: L. A. Sazanov, “The mechanism of coupling between electron transfer and proton
translocation in respiratory complex I,” Journal of Bioenergetics and Biomembranes,
vol. 46, no. 4. Springer, pp. 247–253, 2014.
ista: Sazanov LA. 2014. The mechanism of coupling between electron transfer and
proton translocation in respiratory complex I. Journal of Bioenergetics and Biomembranes.
46(4), 247–253.
mla: Sazanov, Leonid A. “The Mechanism of Coupling between Electron Transfer and
Proton Translocation in Respiratory Complex I.” Journal of Bioenergetics and
Biomembranes, vol. 46, no. 4, Springer, 2014, pp. 247–53, doi:10.1007/s10863-014-9554-z.
short: L.A. Sazanov, Journal of Bioenergetics and Biomembranes 46 (2014) 247–253.
date_created: 2018-12-11T11:55:01Z
date_published: 2014-08-01T00:00:00Z
date_updated: 2021-01-12T06:54:28Z
day: '01'
doi: 10.1007/s10863-014-9554-z
extern: 1
intvolume: ' 46'
issue: '4'
month: '08'
page: 247 - 253
publication: Journal of Bioenergetics and Biomembranes
publication_status: published
publisher: Springer
publist_id: '5104'
quality_controlled: 0
status: public
title: The mechanism of coupling between electron transfer and proton translocation
in respiratory complex I
type: journal_article
volume: 46
year: '2014'
...
---
_id: '1989'
abstract:
- lang: eng
text: During animal cell division, the cleavage furrow is positioned by microtubules
that signal to the actin cortex at the cell midplane. We developed a cell-free
system to recapitulate cytokinesis signaling using cytoplasmic extract from Xenopus
eggs. Microtubules grew out as asters from artificial centrosomes and met to organize
antiparallel overlap zones. These zones blocked the interpenetration of neighboring
asters and recruited cytokinesis midzone proteins, including the chromosomal passenger
complex (CPC) and centralspindlin. The CPC was transported to overlap zones, which
required two motor proteins, Kif4A and a Kif20A paralog. Using supported lipid
bilayers to mimic the plasma membrane, we observed the recruitment of cleavage
furrow markers, including an active RhoA reporter, at microtubule overlaps. This
system opens further approaches to understanding the biophysics of cytokinesis
signaling.
acknowledgement: 'This work was supported by NIH grant GM39565 (T.J.M.); MBL fellowships
from the Evans Foundation, MBL Associates, and the Colwin Fund (T.J.M. and C.M.F.);
HFSP fellowship LT000466/2012-L (M.L.); and NIH grant GM103785 (M.W.). '
author:
- first_name: Phuong
full_name: Nguyen, Phuong A
last_name: Nguyen
- first_name: Aaron
full_name: Groen, Aaron C
last_name: Groen
- first_name: Martin
full_name: Martin Loose
id: 462D4284-F248-11E8-B48F-1D18A9856A87
last_name: Loose
orcid: 0000-0001-7309-9724
- first_name: Keisuke
full_name: 'Ishihara, Keisuke '
last_name: Ishihara
- first_name: Martin
full_name: 'Wühr, Martin '
last_name: Wühr
- first_name: Christine
full_name: Field, Christine M
last_name: Field
- first_name: Timothy
full_name: Mitchison, Timothy J
last_name: Mitchison
citation:
ama: Nguyen P, Groen A, Loose M, et al. Spatial organization of cytokinesis signaling
reconstituted in a cell-free system. Science. 2014;346(6206):244-247. doi:10.1126/science.1256773
apa: Nguyen, P., Groen, A., Loose, M., Ishihara, K., Wühr, M., Field, C., &
Mitchison, T. (2014). Spatial organization of cytokinesis signaling reconstituted
in a cell-free system. Science. American Association for the Advancement
of Science. https://doi.org/10.1126/science.1256773
chicago: Nguyen, Phuong, Aaron Groen, Martin Loose, Keisuke Ishihara, Martin Wühr,
Christine Field, and Timothy Mitchison. “Spatial Organization of Cytokinesis Signaling
Reconstituted in a Cell-Free System.” Science. American Association for
the Advancement of Science, 2014. https://doi.org/10.1126/science.1256773.
ieee: P. Nguyen et al., “Spatial organization of cytokinesis signaling reconstituted
in a cell-free system,” Science, vol. 346, no. 6206. American Association
for the Advancement of Science, pp. 244–247, 2014.
ista: Nguyen P, Groen A, Loose M, Ishihara K, Wühr M, Field C, Mitchison T. 2014.
Spatial organization of cytokinesis signaling reconstituted in a cell-free system.
Science. 346(6206), 244–247.
mla: Nguyen, Phuong, et al. “Spatial Organization of Cytokinesis Signaling Reconstituted
in a Cell-Free System.” Science, vol. 346, no. 6206, American Association
for the Advancement of Science, 2014, pp. 244–47, doi:10.1126/science.1256773.
short: P. Nguyen, A. Groen, M. Loose, K. Ishihara, M. Wühr, C. Field, T. Mitchison,
Science 346 (2014) 244–247.
date_created: 2018-12-11T11:55:04Z
date_published: 2014-10-10T00:00:00Z
date_updated: 2021-01-12T06:54:32Z
day: '10'
doi: 10.1126/science.1256773
extern: 1
intvolume: ' 346'
issue: '6206'
month: '10'
page: 244 - 247
publication: Science
publication_status: published
publisher: American Association for the Advancement of Science
publist_id: '5093'
quality_controlled: 0
status: public
title: Spatial organization of cytokinesis signaling reconstituted in a cell-free
system
type: journal_article
volume: 346
year: '2014'
...
---
_id: '1990'
abstract:
- lang: eng
text: 'Bacterial cytokinesis is commonly initiated by the Z-ring, a cytoskeletal
structure that assembles at the site of division. Its primary component is FtsZ,
a tubulin superfamily GTPase, which is recruited to the membrane by the actin-related
protein FtsA. Both proteins are required for the formation of the Z-ring, but
if and how they influence each other''s assembly dynamics is not known. Here,
we reconstituted FtsA-dependent recruitment of FtsZ polymers to supported membranes,
where both proteins self-organize into complex patterns, such as fast-moving filament
bundles and chirally rotating rings. Using fluorescence microscopy and biochemical
perturbations, we found that these large-scale rearrangements of FtsZ emerge from
its polymerization dynamics and a dual, antagonistic role of FtsA: recruitment
of FtsZ filaments to the membrane and negative regulation of FtsZ organization.
Our findings provide a model for the initial steps of bacterial cell division
and illustrate how dynamic polymers can self-organize into large-scale structures.'
acknowledgement: M.L. is supported by fellowships from EMBO (ALTF 394-2011) and HFSP
(LT000466/2012). Cytoskeleton dynamics research in the T.J.M. group is supported
by NIH-GM39565.
author:
- first_name: Martin
full_name: Martin Loose
id: 462D4284-F248-11E8-B48F-1D18A9856A87
last_name: Loose
orcid: 0000-0001-7309-9724
- first_name: Timothy
full_name: Mitchison, Timothy J
last_name: Mitchison
citation:
ama: Loose M, Mitchison T. The bacterial cell division proteins ftsA and ftsZ self-organize
into dynamic cytoskeletal patterns. Nature Cell Biology. 2014;16(1):38-46.
doi:10.1038/ncb2885
apa: Loose, M., & Mitchison, T. (2014). The bacterial cell division proteins
ftsA and ftsZ self-organize into dynamic cytoskeletal patterns. Nature Cell
Biology. Nature Publishing Group. https://doi.org/10.1038/ncb2885
chicago: Loose, Martin, and Timothy Mitchison. “The Bacterial Cell Division Proteins
FtsA and FtsZ Self-Organize into Dynamic Cytoskeletal Patterns.” Nature Cell
Biology. Nature Publishing Group, 2014. https://doi.org/10.1038/ncb2885.
ieee: M. Loose and T. Mitchison, “The bacterial cell division proteins ftsA and
ftsZ self-organize into dynamic cytoskeletal patterns,” Nature Cell Biology,
vol. 16, no. 1. Nature Publishing Group, pp. 38–46, 2014.
ista: Loose M, Mitchison T. 2014. The bacterial cell division proteins ftsA and
ftsZ self-organize into dynamic cytoskeletal patterns. Nature Cell Biology. 16(1),
38–46.
mla: Loose, Martin, and Timothy Mitchison. “The Bacterial Cell Division Proteins
FtsA and FtsZ Self-Organize into Dynamic Cytoskeletal Patterns.” Nature Cell
Biology, vol. 16, no. 1, Nature Publishing Group, 2014, pp. 38–46, doi:10.1038/ncb2885.
short: M. Loose, T. Mitchison, Nature Cell Biology 16 (2014) 38–46.
date_created: 2018-12-11T11:55:05Z
date_published: 2014-01-01T00:00:00Z
date_updated: 2021-01-12T06:54:33Z
day: '01'
doi: 10.1038/ncb2885
extern: 1
intvolume: ' 16'
issue: '1'
month: '01'
page: 38 - 46
publication: Nature Cell Biology
publication_status: published
publisher: Nature Publishing Group
publist_id: '5094'
quality_controlled: 0
status: public
title: The bacterial cell division proteins ftsA and ftsZ self-organize into dynamic
cytoskeletal patterns
type: journal_article
volume: 16
year: '2014'
...
---
_id: '1996'
abstract:
- lang: eng
text: Auxin polar transport, local maxima, and gradients have become an importantmodel
system for studying self-organization. Auxin distribution is regulated by auxin-dependent
positive feedback loops that are not well-understood at the molecular level. Previously,
we showed the involvement of the RHO of Plants (ROP) effector INTERACTOR of CONSTITUTIVELY
active ROP 1 (ICR1) in regulation of auxin transport and that ICR1 levels are
posttranscriptionally repressed at the site of maximum auxin accumulation at the
root tip. Here, we show that bimodal regulation of ICR1 levels by auxin is essential
for regulating formation of auxin local maxima and gradients. ICR1 levels increase
concomitant with increase in auxin response in lateral root primordia, cotyledon
tips, and provascular tissues. However, in the embryo hypophysis and root meristem,
when auxin exceeds critical levels, ICR1 is rapidly destabilized by an SCF(TIR1/AFB)
[SKP, Cullin, F-box (transport inhibitor response 1/auxin signaling F-box protein)]-dependent
auxin signaling mechanism. Furthermore, ectopic expression of ICR1 in the embryo
hypophysis resulted in reduction of auxin accumulation and concomitant root growth
arrest. ICR1 disappeared during root regeneration and lateral root initiation
concomitantly with the formation of a local auxin maximum in response to external
auxin treatments and transiently after gravitropic stimulation. Destabilization
of ICR1 was impaired after inhibition of auxin transport and signaling, proteasome
function, and protein synthesis. A mathematical model based on these findings
shows that an in vivo-like auxin distribution, rootward auxin flux, and shootward
reflux can be simulated without assuming preexisting tissue polarity. Our experimental
results and mathematical modeling indicate that regulation of auxin distribution
is tightly associated with auxin-dependent ICR1 levels.
author:
- first_name: Ora
full_name: Hazak, Ora
last_name: Hazak
- first_name: Uri
full_name: Obolski, Uri
last_name: Obolski
- first_name: Tomas
full_name: Prat, Tomas
id: 3DA3BFEE-F248-11E8-B48F-1D18A9856A87
last_name: Prat
- first_name: Jiří
full_name: Friml, Jiří
id: 4159519E-F248-11E8-B48F-1D18A9856A87
last_name: Friml
orcid: 0000-0002-8302-7596
- first_name: Lilach
full_name: Hadany, Lilach
last_name: Hadany
- first_name: Shaul
full_name: Yalovsky, Shaul
last_name: Yalovsky
citation:
ama: Hazak O, Obolski U, Prat T, Friml J, Hadany L, Yalovsky S. Bimodal regulation
of ICR1 levels generates self-organizing auxin distribution. PNAS. 2014;111(50):E5471-E5479.
doi:10.1073/pnas.1413918111
apa: Hazak, O., Obolski, U., Prat, T., Friml, J., Hadany, L., & Yalovsky, S.
(2014). Bimodal regulation of ICR1 levels generates self-organizing auxin distribution.
PNAS. National Academy of Sciences. https://doi.org/10.1073/pnas.1413918111
chicago: Hazak, Ora, Uri Obolski, Tomas Prat, Jiří Friml, Lilach Hadany, and Shaul
Yalovsky. “Bimodal Regulation of ICR1 Levels Generates Self-Organizing Auxin Distribution.”
PNAS. National Academy of Sciences, 2014. https://doi.org/10.1073/pnas.1413918111.
ieee: O. Hazak, U. Obolski, T. Prat, J. Friml, L. Hadany, and S. Yalovsky, “Bimodal
regulation of ICR1 levels generates self-organizing auxin distribution,” PNAS,
vol. 111, no. 50. National Academy of Sciences, pp. E5471–E5479, 2014.
ista: Hazak O, Obolski U, Prat T, Friml J, Hadany L, Yalovsky S. 2014. Bimodal regulation
of ICR1 levels generates self-organizing auxin distribution. PNAS. 111(50), E5471–E5479.
mla: Hazak, Ora, et al. “Bimodal Regulation of ICR1 Levels Generates Self-Organizing
Auxin Distribution.” PNAS, vol. 111, no. 50, National Academy of Sciences,
2014, pp. E5471–79, doi:10.1073/pnas.1413918111.
short: O. Hazak, U. Obolski, T. Prat, J. Friml, L. Hadany, S. Yalovsky, PNAS 111
(2014) E5471–E5479.
date_created: 2018-12-11T11:55:07Z
date_published: 2014-12-16T00:00:00Z
date_updated: 2021-01-12T06:54:35Z
day: '16'
department:
- _id: JiFr
doi: 10.1073/pnas.1413918111
intvolume: ' 111'
issue: '50'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4273421/
month: '12'
oa: 1
oa_version: Submitted Version
page: E5471 - E5479
publication: PNAS
publication_status: published
publisher: National Academy of Sciences
publist_id: '5083'
quality_controlled: '1'
scopus_import: 1
status: public
title: Bimodal regulation of ICR1 levels generates self-organizing auxin distribution
type: journal_article
user_id: 4435EBFC-F248-11E8-B48F-1D18A9856A87
volume: 111
year: '2014'
...