SASDAW6

Iron-sulfur cluster assembly scaffold IscU monomer

Data type: SASBDB experimental data Status: Published Curve type: Single concentration Last updated: 2023-05-25T11:21:52.654103+02:00

Reduced levels of frataxin, an essential protein of as yet unknown function, are responsible for causing the neurodegenerative pathology Friedreich’s ataxia. Independent reports have linked frataxin to iron–sulphur cluster assembly through interactions with the two central components of this machinery: desulphurase Nfs1/IscS and the scaffold protein Isu/IscU. In this study, we use a combination of biophysical methods to define the structural bases of the interaction of CyaY (the bacterial orthologue of frataxin) with the IscS/IscU complex. We show that CyaY binds IscS as a monomer in a pocket between the active site and the IscS dimer interface. Recognition does not require iron and occurs through electrostatic interactions of complementary charged residues. Mutations at the complex interface affect the rates of enzymatic cluster formation. CyaY binding strengthens the affinity of the IscS/IscU complex. Our data suggest a new paradigm for understanding the role of frataxin as a regulator of IscS functions.

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1. Samples, Components and Experimental Conditions Sample & Experiment

Sample 1 · Iron-sulfur cluster assembly scaffold IscU monomer

Concentration— – 2.5 mg/mlBuffer / pH20 mM Tris-HCl 150 mM NaCl 10 mM β-mercaptoethanol / 8.0
Experimental temperature15.0 Facility / beamlineDORIS III, DESY / EMBL X33
Wavelength0.15 nmExposure30.0 s × 4

Molecular Components

ComponentType / organismUniProt and ConstructOligomeric StateMolecular weight
Iron-sulfur cluster assembly scaffold protein IscU
View sequence
MAYSEKVIDHYENPRNVGSLDKKDSNVGTGMVGAPACGDVMQLQIKVDDNGIIEDAKFKTYGCGSAIASSSLITEWVKGKSLEEAGAIKNSQIAEELELPPVKVHCSILAEDAIKAAIADYKAKQGLEHHHHHH
proteinEscherichia coliP0ACD4—–—monomerMolecule count 114.464 kDa

Experimental Curves

CurvePoints / columnsq rangeUncertainty qualityNegative-intensity pointsSource file
12282[3]0.152148–6.23701 1/nmHas uncertainty columnMissing 015sasbdb/entries/w6/sasdaw6/source/SASDAW6.dat
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2. Measurements Reported by SASBDB Reported Results

MetricMethodValueUncertaintyUnit
dmaxP(r)6.4—nm
i0Guinier17.2——
i0P(r)17.2——
mwExperimental14.0—kDa
mwGuinier I(0)14.0—kDa
rgGuinier1.870.006nm
rgP(r)1.86—nm

These values are reported by SASBDB; SAXSdb did not recalculate them from the experimental curve.

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3. Source Fits and Models Source Fits & Models

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4. Source File Index Source Files

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5. Experiment Description and Publication Experiment & Publication

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6. Complete Source Record Complete Source Record

The following content comes directly from the SASBDB entry. Missing values are shown as “—”; SAXSdb does not infer undeclared units.

Open the original SASBDB entry

Buffer and Sample Properties

Buffer name20 mM Tris-HCl 150 mM NaCl 10 mM β-mercaptoethanolBuffer concentration20.0 mM
pH8.0Additives150 mM NaCl and 10 mM β-mercaptoethanol
Buffer description—
Purity measurement method—Extinction coefficient—
Absorbance—Scattering contrast—
Specific volume / dry volume— / —Mixture / deuteration— / —

Acquisition Conditions and Instrument

Measurement date2009-11-05Storage / measurement temperature15.0 / 15.0
Exposure time30.0Frames4
Wavelength0.15Sample-to-detector distance2.7
SourceX-ray synchrotronDetectorPilatus 1M-W
Facility / beamlineDORIS III, DESY / EMBL X33 · Hamburg, Germany
q range0.152 – 6.237Sample volume / flow rate— / —

Original SASBDB Plots

Experimental I(q)
Experimental I(q)
Experimental I(q), log-log
Experimental I(q), log-log
Guinier plot
Guinier plot
Kratky plot
Kratky plot
P(r) plot
P(r) plot

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All source fields (unfiltered)

Every source field is expanded here, including empty values, list members and fields already shown above.

summary.json:182 field values
Field pathRaw value
codeSASDAW6
statusPublished
type_of_curveSingle concentration
angular_unit1/nm
project.titleStructural bases for the interaction of frataxin with the central components of iron-sulphur cluster assembly.
project.publication.titleStructural bases for the interaction of frataxin with the central components of iron-sulphur cluster assembly.
project.publication.author_listPrischi F, Konarev PV, Iannuzzi C, Pastore C, Adinolfi S, Martin SR, Svergun DI, Pastore A
project.publication.journalNat Commun
project.publication.doi10.1038/ncomms1097
project.publication.pmid20981023
project.publication.published_date2010 Oct 19
project.statusreleased
project.submitted_datenull
project.released_date2015-07-07
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experiment.instrument.detector.namePilatus 1M-W
experiment.instrument.detector.resolution0.172
experiment.instrument.nameDORIS III, DESY
experiment.instrument.cityHamburg
experiment.instrument.countryGermany
experiment.instrument.beamline_nameEMBL X33
experiment.instrument.beam_geometry0.60
experiment.instrument.type_of_sourceX-ray synchrotron
experiment.instrument.point_sourcenull
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experiment.instrument.sample_path_lengthnull
experiment.instrument.line_collimation_slitlengthnull
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experiment.instrument.beam_profile_ahnull
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experiment.sample.molecule[0].long_nameIron-sulfur cluster assembly scaffold protein IscU
experiment.sample.molecule[0].short_namenull
experiment.sample.molecule[0].sequenceMAYSEKVIDHYENPRNVGSLDKKDSNVGTGMVGAPACGDVMQLQIKVDDNGIIEDAKFKTYGCGSAIASSSLITEWVKGK SLEEAGAIKNSQIAEELELPPVKVHCSILAEDAIKAAIADYKAKQGLEHHHHHH
experiment.sample.molecule[0].organismEscherichia coli
experiment.sample.molecule[0].uniprot_codeP0ACD4
experiment.sample.molecule[0].uniprot_range_firstnull
experiment.sample.molecule[0].uniprot_range_lastnull
experiment.sample.molecule[0].oligomerizationmonomer
experiment.sample.molecule[0].molecular_typeprotein
experiment.sample.molecule[0].uniprot_sequenceMAYSEKVIDHYENPRNVGSFDNNDENVGSGMVGAPACGDVMKLQIKVNDEGIIEDARFKT YGCGSAIASSSLVTEWVKGKSLDEAQAIKNTDIAEELELPPVKIHCSILAEDAIKAAIAD YKSKREAK
experiment.sample.molecule[0].mw14.464
experiment.sample.molecule[0].total_mw14.464
experiment.sample.molecule[0].number_molecules1
experiment.sample.molecule[0].complex_statenull
experiment.sample.molecule[0].deuterationnull
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experiment.sample.buffer.name20 mM Tris-HCl 150 mM NaCl 10 mM β-mercaptoethanol
experiment.sample.buffer.concentration_unitmM
experiment.sample.buffer.commentnull
experiment.sample.buffer.additive150 mM NaCl and 10 mM β-mercaptoethanol
experiment.sample.buffer.concentration20.0
experiment.sample.buffer.pkanull
experiment.sample.buffer.ph8.0
experiment.sample.buffer.deuterationnull
experiment.sample.purity_methodnull
experiment.sample.nameIron-sulfur cluster assembly scaffold IscU monomer
experiment.sample.ext_coefficientnull
experiment.sample.contrastnull
experiment.sample.specific_volnull
experiment.sample.dry_volnull
experiment.sample.absorbptionnull
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experiment.sample.mixturenull
experiment.contributor[0].affiliation[0].short_nameEMBL-Hamburg
experiment.contributor[0].affiliation[0].addressNotkestraße 85, Geb. 25A, 22607 Hamburg, Deutschland, Germany
experiment.contributor[0].affiliation[0].full_nameEuropean Molecular Biology Laboratory (EMBL) - Hamburg outstation
experiment.contributor[0].affiliation[0].webpagehttp://www.embl-hamburg.de/index.php
experiment.contributor[0].contributor_namePetr
experiment.contributor[0].contributor_surnameKonarev
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i0_calibration_standardnull
descriptionReduced levels of frataxin, an essential protein of as yet unknown function, are responsible for causing the neurodegenerative pathology Friedreich’s ataxia. Independent reports have linked frataxin to iron–sulphur cluster assembly through interactions with the two central components of this machinery: desulphurase Nfs1/IscS and the scaffold protein Isu/IscU. In this study, we use a combination of biophysical methods to define the structural bases of the interaction of CyaY (the bacterial orthologue of frataxin) with the IscS/IscU complex. We show that CyaY binds IscS as a monomer in a pocket between the active site and the IscS dimer interface. Recognition does not require iron and occurs through electrostatic interactions of complementary charged residues. Mutations at the complex interface affect the rates of enzymatic cluster formation. CyaY binding strengthens the affinity of the IscS/IscU complex. Our data suggest a new paradigm for understanding the role of frataxin as a regulator of IscS functions.
experiment_descriptionnull
tags[0]X33
intensity_unitnull
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experimental_mw_errornull
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last_modified2023-05-25T11:21:52.654103+02:00
bragg_peak[]
manifest.json:36 field values
Field pathRaw value
codeSASDAW6
statussuccess
started_at2026-08-11T15:17:04.263585+00:00
finished_at2026-08-11T15:17:14.107505+00:00
source_last_modified2023-05-25T11:21:52.654103+02:00
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View the complete summary.json source
{
  "code": "SASDAW6",
  "status": "Published",
  "type_of_curve": "Single concentration",
  "angular_unit": "1/nm",
  "project": {
    "title": "Structural bases for the interaction of frataxin with the central components of iron-sulphur cluster assembly.",
    "publication": {
      "title": "Structural bases for the interaction of frataxin with the central components of iron-sulphur cluster assembly.",
      "author_list": "Prischi F, Konarev PV, Iannuzzi C, Pastore C, Adinolfi S, Martin SR, Svergun DI, Pastore A",
      "journal": "Nat Commun",
      "doi": "10.1038/ncomms1097",
      "pmid": "20981023",
      "published_date": "2010 Oct 19"
    },
    "status": "released",
    "submitted_date": null,
    "released_date": "2015-07-07"
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View the complete manifest.json source
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