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HAMAP rule MF_00331

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General rule information [?]

Accession MF_00331
Dates 1-JUN-2001 (Created)
17-JAN-2023 (Last updated, Version 42)
Name Cys_desulf_IscS
Scope
Bacteria
Archaea
Templates P0A6B7 (ISCS_ECOLI); O31269 (ISCS_AZOVI); O29689 (ISCS2_ARCFU); P0A6B9 (ISCS_ECO57): [Recover all]

Propagated annotation [?]


Identifier, protein and gene names [?]

Identifier
ISCS
Protein name
RecName: Full=Cysteine desulfurase IscS;
EC 2.8.1.7;
Gene name
iscS

Comments [?]

case <OC:Escherichia> or <OC:Shigella> or <OC:Salmonella>
Function 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 and selenium atoms from cysteine and selenocysteine 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. Also functions as a selenium delivery protein in the pathway for the biosynthesis of selenophosphate.
else
Function 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 atoms 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.
end case
Catalytic activity RHEA:43892: [sulfur carrier]-H + L-cysteine = [sulfur carrier]-SH + L-alanine
EC 2.8.1.7
Cofactor pyridoxal 5'-phosphate
Pathway Cofactor biosynthesis; iron-sulfur cluster biosynthesis.
Subunit Homodimer. Forms a heterotetramer with IscU, interacts with other sulfur acceptors.
Subcellular location Cytoplasm.
case <OC:Archaea>
Miscellaneous In Archaea the pyridoxal phosphate cofactor is not covalently bound to Lys but ligated by other amino acids.
end case
Similarity Belongs to the class-V pyridoxal-phosphate-dependent aminotransferase family. NifS/IscS subfamily.

Keywords [?]

case <FTTag:IronSulfur>
end case

Gene Ontology [?]

GO:0005737; Cellular component: cytoplasm.
GO:0030170; Molecular function: pyridoxal phosphate binding.
GO:0031071; Molecular function: cysteine desulfurase activity.
case <FTTag:IronSulfur>
GO:0051537; Molecular function: 2 iron, 2 sulfur cluster binding.
end case
GO:0044571; Biological process: [2Fe-2S] cluster assembly.

Cross-references [?]

Pfam PF00266; Aminotran_5; 1;
PIRSF PIRSF005572; NifS; 1;
TIGRFAMs TIGR02006; IscS; 1;
TIGR03402; FeS_nifS; 1;
TIGR03403; nifS_epsilon; 1;
PROSITE PS00595; AA_TRANSFER_CLASS_5; 1;

Features [?]

From: ISCS_ECO57 (P0A6B9)
Key     From     To       Description   Tag   Condition   FTGroup
BINDING     75     76       /ligand="pyridoxal 5'-phosphate" /ligand_id="ChEBI:CHEBI:597326     [AG]-[TS]  
BINDING     203     205       /ligand="pyridoxal 5'-phosphate" /ligand_id="ChEBI:CHEBI:597326     [TS]-x-H  
ACT_SITE     328     328       Cysteine persulfide intermediate     C  
BINDING     328     328       /ligand="[2Fe-2S] cluster" /ligand_id="ChEBI:CHEBI:190135" /ligand_note="ligand shared with IscU" /note="via persulfide group   IronSulfur   C  
BINDING     155     155       /ligand="pyridoxal 5'-phosphate" /ligand_id="ChEBI:CHEBI:597326     N  
BINDING     183     183       /ligand="pyridoxal 5'-phosphate" /ligand_id="ChEBI:CHEBI:597326     Q  
BINDING     243     243       /ligand="pyridoxal 5'-phosphate" /ligand_id="ChEBI:CHEBI:597326     [TS]  
case <OC:Bacteria>
MOD_RES     206     206       N6-(pyridoxal phosphate)lysine     K  
end case

Additional information [?]

Size range 375-410 amino acids
Related rules None
Fusion None
Comments Divergent HALH5 and BACSU; sequences not included in alignment