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Protein

Cysteine desulfurase IscS

Gene

iscS

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

Functioni

Master enzyme that delivers sulfur to a number of partners involved in Fe-S cluster assembly, tRNA modification or cofactor biosynthesis. Catalyzes the removal of elemental sulfur from cysteine to produce alanine. Functions as a sulfur delivery protein for Fe-S cluster synthesis onto IscU, an Fe-S scaffold assembly protein, as well as other S acceptor proteins. Preferentially binds to disordered IscU on which the Fe-S is assembled, IscU converts to the structured state and then dissociates from IscS to transfer the Fe-S to an acceptor protein. Also functions as a selenium delivery protein in the pathway for the biosynthesis of selenophosphate. Transfers sulfur onto 'Cys-456' of ThiI and onto 'Cys-19' of TusA in transpersulfidation reactions.10 Publications

Catalytic activityi

L-cysteine + acceptor = L-alanine + S-sulfanyl-acceptor.UniRule annotation1 Publication

Cofactori

pyridoxal 5'-phosphateUniRule annotation2 Publications

Enzyme regulationi

Treatment with N-ethylmaleimide inhibits sulfur transfer. Activated by ThiI and TusA.3 Publications

Kineticsi

kcat is 8.5 min(-1).1 Publication

Manual assertion based on experiment ini

  1. KM=2.7 µM for L-cysteine1 Publication

    Pathwayi: iron-sulfur cluster biosynthesis

    This protein is involved in the pathway iron-sulfur cluster biosynthesis, which is part of Cofactor biosynthesis.UniRule annotation1 Publication
    View all proteins of this organism that are known to be involved in the pathway iron-sulfur cluster biosynthesis and in Cofactor biosynthesis.

    Sites

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Binding sitei155Pyridoxal phosphateUniRule annotation1
    Binding sitei183Pyridoxal phosphateUniRule annotation1 Publication1
    Binding sitei243Pyridoxal phosphateUniRule annotation1 Publication1
    Active sitei328Cysteine persulfide intermediateUniRule annotation2 Publications1
    Metal bindingi328Iron-sulfur (2Fe-2S); via persulfide group; shared with IscUUniRule annotation1

    GO - Molecular functioni

    • 2 iron, 2 sulfur cluster binding Source: UniProtKB-HAMAP
    • cysteine desulfurase activity Source: EcoCyc
    • metal ion binding Source: UniProtKB-KW
    • pyridoxal phosphate binding Source: EcoCyc
    • selenocysteine lyase activity Source: EcoCyc
    • sulfur carrier activity Source: EcoCyc

    GO - Biological processi

    • [2Fe-2S] cluster assembly Source: UniProtKB-HAMAP
    • iron-sulfur cluster assembly Source: EcoCyc
    • oxazole or thiazole biosynthetic process Source: EcoCyc
    • tRNA pseudouridine synthesis Source: EcoCyc
    Complete GO annotation...

    Keywords - Molecular functioni

    Transferase

    Keywords - Biological processi

    tRNA processing

    Keywords - Ligandi

    2Fe-2S, Iron, Iron-sulfur, Metal-binding, Pyridoxal phosphate

    Enzyme and pathway databases

    BioCyciEcoCyc:G7325-MONOMER.
    ECOL316407:JW2514-MONOMER.
    MetaCyc:G7325-MONOMER.
    UniPathwayiUPA00266.

    Names & Taxonomyi

    Protein namesi
    Recommended name:
    Cysteine desulfurase IscS1 PublicationUniRule annotation (EC:2.8.1.7UniRule annotation1 Publication)
    Alternative name(s):
    NifS protein homolog1 Publication
    ThiI transpersulfidase1 Publication
    TusA transpersulfidase1 Publication
    Gene namesi
    Name:iscSUniRule annotation
    Synonyms:nuvC, yfhO, yzzO
    Ordered Locus Names:b2530, JW2514
    OrganismiEscherichia coli (strain K12)
    Taxonomic identifieri83333 [NCBI]
    Taxonomic lineageiBacteriaProteobacteriaGammaproteobacteriaEnterobacteralesEnterobacteriaceaeEscherichia
    Proteomesi
    • UP000000318 Componenti: Chromosome
    • UP000000625 Componenti: Chromosome

    Organism-specific databases

    EcoGeneiEG12677. iscS.

    Subcellular locationi

    • Cytoplasm UniRule annotationCurated

    GO - Cellular componenti

    • cytosol Source: EcoCyc
    Complete GO annotation...

    Keywords - Cellular componenti

    Cytoplasm

    Pathology & Biotechi

    Disruption phenotypei

    Cells lacking this gene lose sulfurtransferase activity and require thiamine and nicotinic acid for growth. Under aerobic conditions the deletion of IscS causes an auxotrophy for thiamine and nicotinic acid, whereas under anaerobic conditions, only nicotinic acid s required.2 Publications

    Mutagenesis

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Mutagenesisi328C → A: Loss of cysteine desulfurization. 1 Publication1
    Mutagenesisi376 – 404Missing : Normal cysteine desulfurase activity, decreased binding to IscU, decreased sulfur transfer to IscU, decreased Fe-S cluster assembly. 1 PublicationAdd BLAST29

    PTM / Processingi

    Molecule processing

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    ChainiPRO_00001502641 – 404Cysteine desulfurase IscSAdd BLAST404

    Amino acid modifications

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Modified residuei206N6-(pyridoxal phosphate)lysineUniRule annotation1 Publication1

    Proteomic databases

    EPDiP0A6B7.
    PaxDbiP0A6B7.
    PRIDEiP0A6B7.

    Interactioni

    Subunit structurei

    Homodimer. The homodimer interacts with IscU and TusA, other S acceptors. Each subunit of the IscS dimer contacts a IscU monomer.4 Publications

    Binary interactionsi

    WithEntry#Exp.IntActNotes
    iscUP0ACD48EBI-550055,EBI-561646
    rhdAP521972EBI-550055,EBI-7906952From a different organism.
    tusAP0A8905EBI-550055,EBI-561780

    Protein-protein interaction databases

    BioGridi4263511. 524 interactors.
    DIPiDIP-29109N.
    IntActiP0A6B7. 45 interactors.
    MINTiMINT-236550.
    STRINGi511145.b2530.

    Structurei

    Secondary structure

    1404
    Legend: HelixTurnBeta strandPDB Structure known for this area
    Show more details
    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Beta strandi4 – 6Combined sources3
    Turni9 – 11Combined sources3
    Helixi17 – 23Combined sources7
    Helixi24 – 26Combined sources3
    Helixi42 – 62Combined sources21
    Helixi66 – 68Combined sources3
    Beta strandi69 – 73Combined sources5
    Helixi75 – 90Combined sources16
    Helixi91 – 93Combined sources3
    Beta strandi96 – 100Combined sources5
    Helixi105 – 116Combined sources12
    Beta strandi120 – 124Combined sources5
    Helixi134 – 140Combined sources7
    Beta strandi145 – 149Combined sources5
    Turni155 – 157Combined sources3
    Helixi163 – 173Combined sources11
    Beta strandi176 – 180Combined sources5
    Turni182 – 187Combined sources6
    Turni192 – 194Combined sources3
    Beta strandi198 – 204Combined sources7
    Turni205 – 208Combined sources4
    Beta strandi214 – 218Combined sources5
    Turni220 – 223Combined sources4
    Turni235 – 239Combined sources5
    Helixi246 – 279Combined sources34
    Turni280 – 283Combined sources4
    Beta strandi287 – 291Combined sources5
    Turni293 – 295Combined sources3
    Beta strandi300 – 305Combined sources6
    Helixi310 – 316Combined sources7
    Turni317 – 319Combined sources3
    Helixi337 – 342Combined sources6
    Helixi346 – 350Combined sources5
    Beta strandi352 – 356Combined sources5
    Helixi363 – 382Combined sources20
    Helixi385 – 390Combined sources6

    3D structure databases

    Select the link destinations:
    PDBei
    RCSB PDBi
    PDBji
    Links Updated
    PDB entryMethodResolution (Å)ChainPositionsPDBsum
    1P3WX-ray2.10A/B1-404[»]
    ProteinModelPortaliP0A6B7.
    SMRiP0A6B7.
    ModBaseiSearch...
    MobiDBiSearch...

    Miscellaneous databases

    EvolutionaryTraceiP0A6B7.

    Family & Domainsi

    Region

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Regioni75 – 76Pyridoxal phosphate bindingUniRule annotation2
    Regioni203 – 205Pyridoxal phosphate bindingUniRule annotation1 Publication3

    Domaini

    The C-terminus (residues 376-404) is important for interaction with IscU.1 Publication

    Sequence similaritiesi

    Belongs to the class-V pyridoxal-phosphate-dependent aminotransferase family. NifS/IscS subfamily.UniRule annotation

    Phylogenomic databases

    eggNOGiENOG4105C3J. Bacteria.
    COG1104. LUCA.
    HOGENOMiHOG000017510.
    InParanoidiP0A6B7.
    KOiK04487.
    OMAiEPIQSGG.
    PhylomeDBiP0A6B7.

    Family and domain databases

    Gene3Di3.40.640.10. 1 hit.
    3.90.1150.10. 1 hit.
    HAMAPiMF_00331. Cys_desulf_IscS. 1 hit.
    InterProiIPR000192. Aminotrans_V_dom.
    IPR020578. Aminotrans_V_PyrdxlP_BS.
    IPR010240. Cys_deSase_IscS.
    IPR016454. Cysteine_dSase.
    IPR015424. PyrdxlP-dep_Trfase.
    IPR015421. PyrdxlP-dep_Trfase_major_sub1.
    IPR015422. PyrdxlP-dep_Trfase_major_sub2.
    [Graphical view]
    PfamiPF00266. Aminotran_5. 1 hit.
    [Graphical view]
    PIRSFiPIRSF005572. NifS. 1 hit.
    SUPFAMiSSF53383. SSF53383. 1 hit.
    TIGRFAMsiTIGR02006. IscS. 1 hit.
    PROSITEiPS00595. AA_TRANSFER_CLASS_5. 1 hit.
    [Graphical view]

    Sequencei

    Sequence statusi: Complete.

    P0A6B7-1 [UniParc]FASTAAdd to basket

    « Hide

            10         20         30         40         50
    MKLPIYLDYS ATTPVDPRVA EKMMQFMTMD GTFGNPASRS HRFGWQAEEA
    60 70 80 90 100
    VDIARNQIAD LVGADPREIV FTSGATESDN LAIKGAANFY QKKGKHIITS
    110 120 130 140 150
    KTEHKAVLDT CRQLEREGFE VTYLAPQRNG IIDLKELEAA MRDDTILVSI
    160 170 180 190 200
    MHVNNEIGVV QDIAAIGEMC RARGIIYHVD ATQSVGKLPI DLSQLKVDLM
    210 220 230 240 250
    SFSGHKIYGP KGIGALYVRR KPRVRIEAQM HGGGHERGMR SGTLPVHQIV
    260 270 280 290 300
    GMGEAYRIAK EEMATEMERL RGLRNRLWNG IKDIEEVYLN GDLEHGAPNI
    310 320 330 340 350
    LNVSFNYVEG ESLIMALKDL AVSSGSACTS ASLEPSYVLR ALGLNDELAH
    360 370 380 390 400
    SSIRFSLGRF TTEEEIDYTI ELVRKSIGRL RDLSPLWEMY KQGVDLNSIE

    WAHH
    Length:404
    Mass (Da):45,090
    Last modified:June 7, 2005 - v1
    Checksum:i1E4F2E6F9CD266B0
    GO

    Experimental Info

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Sequence conflicti31G → D AA sequence (PubMed:8663056).Curated1
    Sequence conflicti34G → F AA sequence (PubMed:8663056).Curated1
    Sequence conflicti37 – 38AS → NA AA sequence (PubMed:8663056).Curated2
    Sequence conflicti118G → L AA sequence (PubMed:8663056).Curated1
    Sequence conflicti126P → M AA sequence (PubMed:8663056).Curated1
    Sequence conflicti320L → I AA sequence (PubMed:8663056).Curated1
    Sequence conflicti326 – 327SA → YL AA sequence (PubMed:8663056).Curated2
    Sequence conflicti339L → V AA sequence (PubMed:8663056).Curated1

    Sequence databases

    Select the link destinations:
    EMBLi
    GenBanki
    DDBJi
    Links Updated
    U00096 Genomic DNA. Translation: AAT48142.1.
    AP009048 Genomic DNA. Translation: BAA16424.1.
    RefSeqiWP_001295373.1. NZ_LN832404.1.
    YP_026169.1. NC_000913.3.

    Genome annotation databases

    EnsemblBacteriaiAAT48142; AAT48142; b2530.
    BAA16424; BAA16424; BAA16424.
    GeneIDi947004.
    KEGGiecj:JW2514.
    eco:b2530.
    PATRICi32120457. VBIEscCol129921_2631.

    Cross-referencesi

    Sequence databases

    Select the link destinations:
    EMBLi
    GenBanki
    DDBJi
    Links Updated
    U00096 Genomic DNA. Translation: AAT48142.1.
    AP009048 Genomic DNA. Translation: BAA16424.1.
    RefSeqiWP_001295373.1. NZ_LN832404.1.
    YP_026169.1. NC_000913.3.

    3D structure databases

    Select the link destinations:
    PDBei
    RCSB PDBi
    PDBji
    Links Updated
    PDB entryMethodResolution (Å)ChainPositionsPDBsum
    1P3WX-ray2.10A/B1-404[»]
    ProteinModelPortaliP0A6B7.
    SMRiP0A6B7.
    ModBaseiSearch...
    MobiDBiSearch...

    Protein-protein interaction databases

    BioGridi4263511. 524 interactors.
    DIPiDIP-29109N.
    IntActiP0A6B7. 45 interactors.
    MINTiMINT-236550.
    STRINGi511145.b2530.

    Proteomic databases

    EPDiP0A6B7.
    PaxDbiP0A6B7.
    PRIDEiP0A6B7.

    Protocols and materials databases

    Structural Biology KnowledgebaseSearch...

    Genome annotation databases

    EnsemblBacteriaiAAT48142; AAT48142; b2530.
    BAA16424; BAA16424; BAA16424.
    GeneIDi947004.
    KEGGiecj:JW2514.
    eco:b2530.
    PATRICi32120457. VBIEscCol129921_2631.

    Organism-specific databases

    EchoBASEiEB2542.
    EcoGeneiEG12677. iscS.

    Phylogenomic databases

    eggNOGiENOG4105C3J. Bacteria.
    COG1104. LUCA.
    HOGENOMiHOG000017510.
    InParanoidiP0A6B7.
    KOiK04487.
    OMAiEPIQSGG.
    PhylomeDBiP0A6B7.

    Enzyme and pathway databases

    UniPathwayiUPA00266.
    BioCyciEcoCyc:G7325-MONOMER.
    ECOL316407:JW2514-MONOMER.
    MetaCyc:G7325-MONOMER.

    Miscellaneous databases

    EvolutionaryTraceiP0A6B7.
    PROiP0A6B7.

    Family and domain databases

    Gene3Di3.40.640.10. 1 hit.
    3.90.1150.10. 1 hit.
    HAMAPiMF_00331. Cys_desulf_IscS. 1 hit.
    InterProiIPR000192. Aminotrans_V_dom.
    IPR020578. Aminotrans_V_PyrdxlP_BS.
    IPR010240. Cys_deSase_IscS.
    IPR016454. Cysteine_dSase.
    IPR015424. PyrdxlP-dep_Trfase.
    IPR015421. PyrdxlP-dep_Trfase_major_sub1.
    IPR015422. PyrdxlP-dep_Trfase_major_sub2.
    [Graphical view]
    PfamiPF00266. Aminotran_5. 1 hit.
    [Graphical view]
    PIRSFiPIRSF005572. NifS. 1 hit.
    SUPFAMiSSF53383. SSF53383. 1 hit.
    TIGRFAMsiTIGR02006. IscS. 1 hit.
    PROSITEiPS00595. AA_TRANSFER_CLASS_5. 1 hit.
    [Graphical view]
    ProtoNetiSearch...

    Entry informationi

    Entry nameiISCS_ECOLI
    AccessioniPrimary (citable) accession number: P0A6B7
    Secondary accession number(s): P39171
    , P76581, P76992, Q8XA86
    Entry historyi
    Integrated into UniProtKB/Swiss-Prot: June 7, 2005
    Last sequence update: June 7, 2005
    Last modified: November 2, 2016
    This is version 107 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, Direct protein sequencing, Reference proteome

    Documents

    1. Escherichia coli
      Escherichia coli (strain K12): entries and cross-references to EcoGene
    2. PATHWAY comments
      Index of metabolic and biosynthesis pathways
    3. PDB cross-references
      Index of Protein Data Bank (PDB) cross-references
    4. 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.