B1LNI6 · ISCS_ECOSM
- ProteinCysteine desulfurase IscS
- GeneiscS
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids404 (go to sequence)
- Protein existenceInferred from homology
- Annotation score3/5
Function
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.
Catalytic activity
- [sulfur carrier]-H + L-cysteine = [sulfur carrier]-SH + L-alanine
Cofactor
Pathway
Cofactor biosynthesis; iron-sulfur cluster biosynthesis.
Features
Showing features for binding site, active site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Binding site | 75-76 | pyridoxal 5'-phosphate (UniProtKB | ChEBI) | ||||
Sequence: AT | ||||||
Binding site | 155 | pyridoxal 5'-phosphate (UniProtKB | ChEBI) | ||||
Sequence: N | ||||||
Binding site | 183 | pyridoxal 5'-phosphate (UniProtKB | ChEBI) | ||||
Sequence: Q | ||||||
Binding site | 203-205 | pyridoxal 5'-phosphate (UniProtKB | ChEBI) | ||||
Sequence: SGH | ||||||
Binding site | 243 | pyridoxal 5'-phosphate (UniProtKB | ChEBI) | ||||
Sequence: T | ||||||
Active site | 328 | Cysteine persulfide intermediate | ||||
Sequence: C | ||||||
Binding site | 328 | [2Fe-2S] cluster (UniProtKB | ChEBI); ligand shared with IscU; via persulfide group | ||||
Sequence: C |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | cytoplasm | |
Molecular Function | 2 iron, 2 sulfur cluster binding | |
Molecular Function | cysteine desulfurase activity | |
Molecular Function | metal ion binding | |
Molecular Function | pyridoxal phosphate binding | |
Biological Process | [2Fe-2S] cluster assembly |
Keywords
- Molecular function
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameCysteine desulfurase IscS
- EC number
Gene names
Organism names
- Strain
- Taxonomic lineageBacteria > Pseudomonadota > Gammaproteobacteria > Enterobacterales > Enterobacteriaceae > Escherichia
Accessions
- Primary accessionB1LNI6
Proteomes
Subcellular Location
PTM/Processing
Features
Showing features for chain, modified residue.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_1000119628 | 1-404 | Cysteine desulfurase IscS | |||
Sequence: MKLPIYLDYSATTPVDPRVAEKMMQFMTMDGTFGNPASRSHRFGWQAEEAVDIARNQIADLVGADPREIVFTSGATESDNLAIKGAANFYQKKGKHIITSKTEHKAVLDTCRQLEREGFEVTYLAPQRNGIIDLKELEAAMRDDTILVSIMHVNNEIGVVQDIAAIGEMCRARGIIYHVDATQSVGKLPIDLSQLKVDLMSFSGHKIYGPKGIGALYVRRKPRVRIEAQMHGGGHERGMRSGTLPVHQIVGMGEAYRIAKEEMATEMERLRGLRNRLWNGIKDIEEVYLNGDLEHGAPNILNVSFNYVEGESLIMALKDLAVSSGSACTSASLEPSYVLRALGLNDELAHSSIRFSLGRFTTEEEIDYTIELVRKSIGRLRDLSPLWEMYKQGVDLNSIEWAHH | ||||||
Modified residue | 206 | N6-(pyridoxal phosphate)lysine | ||||
Sequence: K |
Interaction
Subunit
Homodimer. Forms a heterotetramer with IscU, interacts with other sulfur acceptors.
Structure
Sequence
- Sequence statusComplete
- Length404
- Mass (Da)45,090
- Last updated2008-04-29 v1
- Checksum1E4F2E6F9CD266B0
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
CP000970 EMBL· GenBank· DDBJ | ACB18360.1 EMBL· GenBank· DDBJ | Genomic DNA |