Cysteine desulfurase IscS - P0A6B9 (ISCS_ECO57)


Protein Feature View of PDB entries mapped to a UniProtKB sequence  

  • Number of PDB entries for P0A6B9: 4
Master enzyme that delivers sulfur to a number of partners involved in Fe-S cluster assembly, tRNA modification or cofactor biosynthesis (biotin, thiamine, molybdopterin). Catalyzes the removal of elemental sulfur and selenium atoms from cysteine and selenocysteine to produce alanine, then delivers the sulfur to an acceptor protein such as CyaY, IscU, IscX, MoaD/MoeB, ThiI, or TusA. Transfers sulfur to acceptor proteins via a transpersulfidation reaction; the flexibility of the persulfide sulfur-carrying Cys-328 allows it to reach different partners docked on the homodimer surface. May function as a selenium delivery protein in the pathway for the biosynthesis of selenophosphate. UniProt
Catalytic Activity
[sulfur carrier]-H + L-cysteine = [sulfur carrier]-SH + L-alanine UniProt
Pathway Maps
      ESCHER  BiGG
Subunit Structure
Homodimer. The homodimer interacts with CyaY, IscU, IscX, ThiI and TusA via an extended surface across both subunits centered around Cys-328. The binding sites for different partners do not necessarily overlap. Certain pairs of proteins can bind simultaneously to IscS; IscS-IscU-CyaY and IscS-IscU-IscX complexes can be isolated in vitro, but others (IscS-IscU-TusA, IscS-TusA-CyaY or IscS-IscX-TusA) complexes cannot. UniProt
  • Other Gene names: iscS, Z3797, ECs3396
This protein in other organisms (by gene name):
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Data in green originates from UniProtKB  
Variation data (sourced from UniProt) shows non-genetic variation from the ExPASy   and dbSNP   websites.
Data in yellow originates from Pfam  , by interacting with the HMMER3 web site  
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Data in orange originates from the SCOP   (version 1.75) and SCOPe   (version 2.04) classifications.
Data in grey has been calculated using BioJava  . Protein disorder predictions are based on JRONN (Troshin, P. and Barton, G. J. unpublished), a Java implementation of RONN  
  • Red: potentially disorderd region
  • Blue: probably ordered region.
Hydropathy has been calculated using a sliding window of 15 residues and summing up scores from standard hydrophobicity tables.
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  • Blue: hydrophilic.
Data in lilac represent the genomic exon structure projected onto the UniProt sequence.
Data in blue originates from PDB
  • Secstruc: Secondary structure projected from representative PDB entries onto the UniProt sequence.
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Validation Track

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Data in red indicates combined ranges of Homology Models from SBKB   and the Protein Model Portal  
The PDB to UniProt mapping is based on the data provided by the EBI SIFTS project. See also Velankar et al., Nucleic Acids Research 33, D262-265 (2005).
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