HAMAP rule MF_00331
General rule information
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| PURL | https://purl.expasy.org/hamap/rule/MF_00331 |
| Accession | MF_00331 |
| Dates | 1-JUN-2001 (Created)
3-DEC-2024 (Last updated, Version 44) |
| Name | Cys_desulf_IscS |
| Scope(s) |
Bacteria Archaea |
| Template(s) | P0A6B7 (ISCS_ECOLI); O31269 (ISCS_AZOVI); O29689 (ISCS2_ARCFU); P0A6B9 (ISCS_ECO57); [ Recover all ] |
| Triggered by |
HAMAP; MF_00331 (Get profile general information and statistics) |
Propagated annotation
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Identifier, protein and gene names
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| Identifier | ISCS |
| Protein name | RecName: Full=Cysteine desulfurase IscS; EC=2.8.1.7; |
| Gene name | Name=iscS; |
Comments
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| 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 | Reaction=(sulfur carrier)-H + L-cysteine = (sulfur carrier)-SH + L- alanine; Xref=Rhea:RHEA:43892, Rhea:RHEA-COMP:14737, Rhea:RHEA- COMP:14739, ChEBI:CHEBI:29917, ChEBI:CHEBI:35235, ChEBI:CHEBI:57972, ChEBI:CHEBI:64428; EC=2.8.1.7; |
| COFACTOR | Name=pyridoxal 5'-phosphate; Xref=ChEBI:CHEBI:597326; |
| 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
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| Cytoplasm | |
| Transferase | |
| Pyridoxal phosphate | |
| case <FTTag:IronSulfur> | |
| 2Fe-2S | |
| Iron | |
| Iron-sulfur | |
| Metal-binding | |
| end case | |
Gene Ontology
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| 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
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| Pfam | PF00266; Aminotran_5; 1; |
| PIRSF | PIRSF005572; NifS; 1; |
| NCBIfam | TIGR02006; IscS; 1; |
| NCBIfam | TIGR03402; FeS_nifS; 1; |
| NCBIfam | TIGR03403; nifS_epsilon; 1; |
| PROSITE | PS00595; AA_TRANSFER_CLASS_5; 1; |
Features
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| 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 | /note="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 | /note="N6-(pyridoxal phosphate)lysine" | K | ||||||||
| end case | ||||||||||||
Additional information
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| Size range | 375-410 amino acids |
| Related rules |
None |
| Fusion | Nter: None Cter: None |
| Comments | Divergent HALH5 and BACSU; sequences not included in alignment |