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Protein

Iron-sulfur cluster assembly scaffold protein IscU

Gene

iscU

Organism
Escherichia coli (strain K12)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

A scaffold on which IscS assembles Fe-S clusters. Exists as 2 interconverting forms, a structured (S) and disordered (D) form. The D-state is the preferred substrate for IscS. Converts to the S-state when an Fe-S cluster is assembled, which helps it dissociate from IscS to transfer the Fe-S to an acceptor. It is likely that Fe-S cluster coordination is flexible as the role of this complex is to build and then hand off Fe-S clusters.2 Publications

Enzyme regulationi

Carboxymethylation by iodoacetic acid blocks sulfur transfer to this protein.1 Publication

GO - Molecular functioni

  • 2 iron, 2 sulfur cluster binding Source: EcoCyc
  • 4 iron, 4 sulfur cluster binding Source: EcoCyc
  • ferrous iron binding Source: GO_Central
  • identical protein binding Source: IntAct
  • iron-sulfur transferase activity Source: GO_Central

GO - Biological processi

Complete GO annotation...

Enzyme and pathway databases

BioCyciEcoCyc:G7324-MONOMER.
ECOL316407:JW2513-MONOMER.
MetaCyc:G7324-MONOMER.

Names & Taxonomyi

Protein namesi
Recommended name:
Iron-sulfur cluster assembly scaffold protein IscU
Alternative name(s):
Sulfur acceptor protein IscU
Gene namesi
Name:iscU
Synonyms:nifU, yfhN
Ordered Locus Names:b2529, JW2513
OrganismiEscherichia coli (strain K12)
Taxonomic identifieri83333 [NCBI]
Taxonomic lineageiBacteriaProteobacteriaGammaproteobacteriaEnterobacterialesEnterobacteriaceaeEscherichia
Proteomesi
  • UP000000318 Componenti: Chromosome
  • UP000000625 Componenti: Chromosome

Organism-specific databases

EcoGeneiEG13395. iscU.

Subcellular locationi

GO - Cellular componenti

  • cytosol Source: EcoCyc
Complete GO annotation...

Pathology & Biotechi

Mutagenesis

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Mutagenesisi39 – 391D → A, L or V: Stabilizes apo-protein in the S-state (structured). 2 Publications
Mutagenesisi39 – 391D → G: No effect on equilibrium between S- and D-state (disordered). 2 Publications
Mutagenesisi89 – 891K → A: Stabilizes apo-protein in the D-state; Fe-S cluster assembly 3-fold slower than wild-type. 1 Publication
Mutagenesisi90 – 901N → A: Stabilizes apo-protein in the S-state; biphasic Fe-S cluster assembly 7-fold slower than wild-type. 2 Publications
Mutagenesisi90 – 901N → D: Stabilizes apo-protein in the D-state; Fe-S cluster assembly 3-fold slower than wild-type. 2 Publications
Mutagenesisi107 – 1071S → A: Stabilizes apo-protein in the S-state; biphasic Fe-S cluster assembly 7-fold slower than wild-type. 2 Publications
Mutagenesisi111 – 1111E → A: Stabilizes apo-protein in the S-state; biphasic Fe-S cluster assembly 7-fold slower than wild-type. 2 Publications

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Chaini1 – 128128Iron-sulfur cluster assembly scaffold protein IscUPRO_0000166184Add
BLAST

Proteomic databases

EPDiP0ACD4.
PaxDbiP0ACD4.
PRIDEiP0ACD4.

Interactioni

Subunit structurei

Homodimer. Forms a heterotetramer with IscS; each subunit of the IscS dimer contacts an IscU monomer.2 Publications

Binary interactionsi

WithEntry#Exp.IntActNotes
itself5EBI-561646,EBI-561646
iscSP0A6B78EBI-561646,EBI-550055

GO - Molecular functioni

  • identical protein binding Source: IntAct

Protein-protein interaction databases

BioGridi4259432. 56 interactions.
851341. 1 interaction.
DIPiDIP-48025N.
IntActiP0ACD4. 15 interactions.
STRINGi511145.b2529.

Structurei

Secondary structure

1
128
Legend: HelixTurnBeta strand
Show more details
Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Beta strandi11 – 133Combined sources
Beta strandi18 – 225Combined sources
Beta strandi25 – 273Combined sources
Beta strandi29 – 346Combined sources
Turni35 – 384Combined sources
Beta strandi39 – 479Combined sources
Beta strandi52 – 598Combined sources
Beta strandi62 – 654Combined sources
Helixi68 – 7710Combined sources
Helixi82 – 876Combined sources
Helixi90 – 978Combined sources
Turni102 – 1043Combined sources
Helixi105 – 12622Combined sources

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
2KQKNMR-A1-128[»]
2L4XNMR-A1-128[»]
ProteinModelPortaliP0ACD4.
SMRiP0ACD4. Positions 1-128.
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiP0ACD4.

Family & Domainsi

Sequence similaritiesi

Belongs to the NifU family.Curated

Phylogenomic databases

eggNOGiENOG4107XTC. Bacteria.
COG0822. LUCA.
HOGENOMiHOG000069228.
InParanoidiP0ACD4.
KOiK04488.
OMAiECGDVMR.
OrthoDBiEOG6GFGQT.
PhylomeDBiP0ACD4.

Family and domain databases

InterProiIPR011339. ISC_FeS_clus_asmbl_IscU.
IPR002871. NIF_FeS_clus_asmbl_NifU_N.
[Graphical view]
PfamiPF01592. NifU_N. 1 hit.
[Graphical view]
TIGRFAMsiTIGR01999. iscU. 1 hit.

Sequencei

Sequence statusi: Complete.

P0ACD4-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MAYSEKVIDH YENPRNVGSF DNNDENVGSG MVGAPACGDV MKLQIKVNDE
60 70 80 90 100
GIIEDARFKT YGCGSAIASS SLVTEWVKGK SLDEAQAIKN TDIAEELELP
110 120
PVKIHCSILA EDAIKAAIAD YKSKREAK
Length:128
Mass (Da):13,849
Last modified:November 22, 2005 - v1
Checksum:i47516021442B6535
GO

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
U00096 Genomic DNA. Translation: AAC75582.1.
AP009048 Genomic DNA. Translation: BAA16423.1.
PIRiH65029.
RefSeqiNP_417024.1. NC_000913.3.
WP_000331707.1. NZ_LN832404.1.

Genome annotation databases

EnsemblBacteriaiAAC75582; AAC75582; b2529.
BAA16423; BAA16423; BAA16423.
GeneIDi947002.
KEGGiecj:JW2513.
eco:b2529.
PATRICi32120455. VBIEscCol129921_2630.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
U00096 Genomic DNA. Translation: AAC75582.1.
AP009048 Genomic DNA. Translation: BAA16423.1.
PIRiH65029.
RefSeqiNP_417024.1. NC_000913.3.
WP_000331707.1. NZ_LN832404.1.

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
2KQKNMR-A1-128[»]
2L4XNMR-A1-128[»]
ProteinModelPortaliP0ACD4.
SMRiP0ACD4. Positions 1-128.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

BioGridi4259432. 56 interactions.
851341. 1 interaction.
DIPiDIP-48025N.
IntActiP0ACD4. 15 interactions.
STRINGi511145.b2529.

Proteomic databases

EPDiP0ACD4.
PaxDbiP0ACD4.
PRIDEiP0ACD4.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsemblBacteriaiAAC75582; AAC75582; b2529.
BAA16423; BAA16423; BAA16423.
GeneIDi947002.
KEGGiecj:JW2513.
eco:b2529.
PATRICi32120455. VBIEscCol129921_2630.

Organism-specific databases

EchoBASEiEB3176.
EcoGeneiEG13395. iscU.

Phylogenomic databases

eggNOGiENOG4107XTC. Bacteria.
COG0822. LUCA.
HOGENOMiHOG000069228.
InParanoidiP0ACD4.
KOiK04488.
OMAiECGDVMR.
OrthoDBiEOG6GFGQT.
PhylomeDBiP0ACD4.

Enzyme and pathway databases

BioCyciEcoCyc:G7324-MONOMER.
ECOL316407:JW2513-MONOMER.
MetaCyc:G7324-MONOMER.

Miscellaneous databases

EvolutionaryTraceiP0ACD4.
PROiP0ACD4.

Family and domain databases

InterProiIPR011339. ISC_FeS_clus_asmbl_IscU.
IPR002871. NIF_FeS_clus_asmbl_NifU_N.
[Graphical view]
PfamiPF01592. NifU_N. 1 hit.
[Graphical view]
TIGRFAMsiTIGR01999. iscU. 1 hit.
ProtoNetiSearch...

Publicationsi

« Hide 'large scale' publications
  1. "Construction of a contiguous 874-kb sequence of the Escherichia coli-K12 genome corresponding to 50.0-68.8 min on the linkage map and analysis of its sequence features."
    Yamamoto Y., Aiba H., Baba T., Hayashi K., Inada T., Isono K., Itoh T., Kimura S., Kitagawa M., Makino K., Miki T., Mitsuhashi N., Mizobuchi K., Mori H., Nakade S., Nakamura Y., Nashimoto H., Oshima T.
    , Oyama S., Saito N., Sampei G., Satoh Y., Sivasundaram S., Tagami H., Takahashi H., Takeda J., Takemoto K., Uehara K., Wada C., Yamagata S., Horiuchi T.
    DNA Res. 4:91-113(1997) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
    Strain: K12 / W3110 / ATCC 27325 / DSM 5911.
  2. Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
    Strain: K12 / MG1655 / ATCC 47076.
  3. "Highly accurate genome sequences of Escherichia coli K-12 strains MG1655 and W3110."
    Hayashi K., Morooka N., Yamamoto Y., Fujita K., Isono K., Choi S., Ohtsubo E., Baba T., Wanner B.L., Mori H., Horiuchi T.
    Mol. Syst. Biol. 2:E1-E5(2006) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
    Strain: K12 / W3110 / ATCC 27325 / DSM 5911.
  4. "Transfer of sulfur from IscS to IscU during Fe/S cluster assembly."
    Urbina H.D., Silberg J.J., Hoff K.G., Vickery L.E.
    J. Biol. Chem. 276:44521-44526(2001) [PubMed] [Europe PMC] [Abstract]
    Cited for: FUNCTION AS A SULFUR ACCEPTOR, INTERACTION WITH ISCS, ENZYME REGULATION, SUBUNIT.
  5. "Disordered form of the scaffold protein IscU is the substrate for iron-sulfur cluster assembly on cysteine desulfurase."
    Kim J.H., Tonelli M., Markley J.L.
    Proc. Natl. Acad. Sci. U.S.A. 109:454-459(2012) [PubMed] [Europe PMC] [Abstract]
    Cited for: FUNCTION, SUBUNIT, MUTAGENESIS OF ASP-39; LYS-89; ASN-90; SER-107 AND GLU-111.
  6. "Three-dimensional structure and determinants of stability of the iron-sulfur cluster scaffold protein IscU from Escherichia coli."
    Kim J.H., Tonelli M., Kim T., Markley J.L.
    Biochemistry 51:5557-5563(2012) [PubMed] [Europe PMC] [Abstract]
    Cited for: STRUCTURE BY NMR OF APO-PROTEIN, MUTAGENESIS OF ASP-39; ASN-90; SER-107 AND GLU-111.

Entry informationi

Entry nameiISCU_ECOLI
AccessioniPrimary (citable) accession number: P0ACD4
Secondary accession number(s): P77310
Entry historyi
Integrated into UniProtKB/Swiss-Prot: November 22, 2005
Last sequence update: November 22, 2005
Last modified: March 16, 2016
This is version 90 of the entry and version 1 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programProkaryotic Protein Annotation Program

Miscellaneousi

Keywords - Technical termi

3D-structure, Complete proteome, Reference proteome

Documents

  1. Escherichia coli
    Escherichia coli (strain K12): entries and cross-references to EcoGene
  2. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  3. SIMILARITY comments
    Index of protein domains and families

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into one UniRef entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.