P0A6B7 (ISCS_ECOLI) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Cysteine desulfurase
EC=2.8.1.7

Alternative name(s):
NifS protein homolog
ThiI transpersulfidase

Gene names

Name:	iscS
Synonyms:	yfhO, yzzO
Ordered Locus Names:	b2530, JW2514

Organism

Escherichia coli (strain K12) [Reference proteome] [HAMAP]

Taxonomic identifier

83333 [NCBI]

Taxonomic lineage

cellular organisms › Bacteria › Proteobacteria › Gammaproteobacteria › Enterobacteriales › Enterobacteriaceae › Escherichia › Escherichia coli

Protein attributes

Sequence length	404 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Catalyzes the removal of elemental sulfur and selenium atoms from cysteine and selenocysteine to produce alanine. Functions as a sulfur delivery protein for NAD, biotin and Fe-S cluster synthesis. Transfers sulfur on 'Cys-456' of ThiI in a transpersulfidation reaction. Transfers sulfur on 'Cys-19' of TusA in a transpersulfidation reaction. Functions also as a selenium delivery protein in the pathway for the biosynthesis of selenophosphate. Ref.11 Ref.13
Catalytic activity	L-cysteine + acceptor = L-alanine + S-sulfanyl-acceptor. HAMAP-Rule MF_00331
Cofactor	Pyridoxal phosphate.
Subunit structure	Homodimer. The homodimer interacts with TusA. Ref.13 Ref.14
Subcellular location	Cytoplasm Probable HAMAP-Rule MF_00331.
Sequence similarities	Belongs to the class-V pyridoxal-phosphate-dependent aminotransferase family. NifS/IscS subfamily.

Ontologies

Keywords
Biological process	tRNA processing
Cellular component	Cytoplasm
Ligand	Pyridoxal phosphate
Molecular function	Transferase
Technical term	3D-structure Complete proteome Direct protein sequencing Reference proteome
Gene Ontology (GO)
Biological_process	cysteine metabolic process Inferred from electronic annotation. Source: InterPro iron-sulfur cluster assembly Inferred from mutant phenotype PubMed 10393315. Source: EcoCyc oxazole or thiazole biosynthetic process Inferred from mutant phenotype Ref.10. Source: EcoCyc tRNA pseudouridine synthesis Inferred from direct assay Ref.5. Source: EcoCyc
Cellular_component	cytoplasm Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular_function	cysteine desulfurase activity Inferred from direct assay Ref.7. Source: EcoCyc pyridoxal phosphate binding Inferred from direct assay Ref.5. Source: EcoCyc selenocysteine lyase activity Inferred from direct assay Ref.7. Source: EcoCyc sulfur carrier activity Inferred from experiment Ref.7. Source: EcoCyc
Complete GO annotation...

Binary interactions

With	Entry	#Exp.	IntAct	Notes
nifU	P0ACD4	8	EBI-550055,EBI-561646

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Chain

1 – 404

404

Cysteine desulfurase HAMAP-Rule MF_00331

PRO_0000150264

Sites

Active site

328

1

Cysteine persulfide intermediate Ref.14

Amino acid modifications

Modified residue

206

1

N6-(pyridoxal phosphate)lysine HAMAP-Rule MF_00331

Experimental info

Mutagenesis

328

1

C → A: Loss of cysteine desulfurization. Ref.7

Sequence conflict

31

1

G → D AA sequence Ref.4

Sequence conflict

34

1

G → F AA sequence Ref.4

Sequence conflict

37 – 38

2

AS → NA AA sequence Ref.4

Sequence conflict

118

1

G → L AA sequence Ref.4

Sequence conflict

126

1

P → M AA sequence Ref.4

Sequence conflict

320

1

L → I AA sequence Ref.4

Sequence conflict

326 – 327

2

SA → YL AA sequence Ref.4

Sequence conflict

339

1

L → V AA sequence Ref.4

Secondary structure

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404

Helix Strand Turn

Details...

Beta strand

4 – 6

3

Turn

9 – 11

3

Helix

17 – 23

7

Helix

24 – 26

3

Helix

42 – 62

21

Helix

66 – 68

3

Beta strand

69 – 73

5

Helix

75 – 90

16

Helix

91 – 93

3

Beta strand

96 – 100

5

Helix

105 – 116

12

Beta strand

120 – 124

5

Helix

134 – 140

7

Beta strand

145 – 149

5

Turn

155 – 157

3

Helix

163 – 173

11

Beta strand

176 – 180

5

Turn

182 – 187

6

Turn

192 – 194

3

Beta strand

198 – 204

7

Turn

205 – 208

4

Beta strand

214 – 218

5

Turn

220 – 223

4

Turn

235 – 239

5

Helix

246 – 279

34

Turn

280 – 283

4

Beta strand

287 – 291

5

Turn

293 – 295

3

Beta strand

300 – 305

6

Helix

310 – 316

7

Turn

317 – 319

3

Helix

337 – 342

6

Helix

346 – 350

5

Beta strand

352 – 356

5

Helix

363 – 382

20

Helix

385 – 390

6

Sequences

	Sequence		Length	Mass (Da)
	P0A6B7 [UniParc]. Last modified June 7, 2005. Version 1. Checksum: 1E4F2E6F9CD266B0	FASTA	404	45,090
	10 20 30 40 50 60 MKLPIYLDYS ATTPVDPRVA EKMMQFMTMD GTFGNPASRS HRFGWQAEEA VDIARNQIAD 70 80 90 100 110 120 LVGADPREIV FTSGATESDN LAIKGAANFY QKKGKHIITS KTEHKAVLDT CRQLEREGFE 130 140 150 160 170 180 VTYLAPQRNG IIDLKELEAA MRDDTILVSI MHVNNEIGVV QDIAAIGEMC RARGIIYHVD 190 200 210 220 230 240 ATQSVGKLPI DLSQLKVDLM SFSGHKIYGP KGIGALYVRR KPRVRIEAQM HGGGHERGMR 250 260 270 280 290 300 SGTLPVHQIV GMGEAYRIAK EEMATEMERL RGLRNRLWNG IKDIEEVYLN GDLEHGAPNI 310 320 330 340 350 360 LNVSFNYVEG ESLIMALKDL AVSSGSACTS ASLEPSYVLR ALGLNDELAH SSIRFSLGRF 370 380 390 400 TTEEEIDYTI ELVRKSIGRL RDLSPLWEMY KQGVDLNSIE WAHH

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"Construction of a contiguous 874-kb sequence of the Escherichia coli-K12 genome corresponding to 50.0-68.8 min on the linkage map and analysis of its sequence features." Yamamoto Y., Aiba H., Baba T., Hayashi K., Inada T., Isono K., Itoh T., Kimura S., Kitagawa M., Makino K., Miki T., Mitsuhashi N., Mizobuchi K., Mori H., Nakade S., Nakamura Y., Nashimoto H., Oshima T. , Oyama S., Saito N., Sampei G., Satoh Y., Sivasundaram S., Tagami H., Takahashi H., Takeda J., Takemoto K., Uehara K., Wada C., Yamagata S., Horiuchi T. DNA Res. 4:91-113(1997) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: K12 / W3110 / ATCC 27325 / DSM 5911.
[2]	"The complete genome sequence of Escherichia coli K-12." Blattner F.R., Plunkett G. III, Bloch C.A., Perna N.T., Burland V., Riley M., Collado-Vides J., Glasner J.D., Rode C.K., Mayhew G.F., Gregor J., Davis N.W., Kirkpatrick H.A., Goeden M.A., Rose D.J., Mau B., Shao Y. Science 277:1453-1474(1997) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: K12 / MG1655 / ATCC 47076.
[3]	"Highly accurate genome sequences of Escherichia coli K-12 strains MG1655 and W3110." Hayashi K., Morooka N., Yamamoto Y., Fujita K., Isono K., Choi S., Ohtsubo E., Baba T., Wanner B.L., Mori H., Horiuchi T. Mol. Syst. Biol. 2:E1-E5(2006) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: K12 / W3110 / ATCC 27325 / DSM 5911.
[4]	"Escherichia coli contains a protein that is homologous in function and N-terminal sequence to the protein encoded by the nifS gene of Azotobacter vinelandii and that can participate in the synthesis of the Fe-S cluster of dihydroxy-acid dehydratase." Flint D.H. J. Biol. Chem. 271:16068-16074(1996) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE OF 1-38; 43-66; 117-127; 212-219; 241-257; 319-339 AND 382-391, CHARACTERIZATION.
[5]	"IscS is a sulfurtransferase for the in vitro biosynthesis of 4-thiouridine in Escherichia coli tRNA." Kambampati R., Lauhon C.T. Biochemistry 38:16561-16568(1999) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE OF 1-16, CHARACTERIZATION. Strain: K12.
[6]	"Comparing the predicted and observed properties of proteins encoded in the genome of Escherichia coli K-12." Link A.J., Robison K., Church G.M. Electrophoresis 18:1259-1313(1997) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE OF 1-12. Strain: K12 / EMG2.
[7]	"Kinetic and mutational studies of three NifS homologs from Escherichia coli: mechanistic difference between L-cysteine desulfurase and L-selenocysteine lyase reactions." Mihara H., Kurihara T., Yoshimura T., Esaki N. J. Biochem. 127:559-567(2000) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE OF 1-9, MUTAGENESIS OF CYS-328. Strain: K12.
[8]	"Functional assignment of the ORF2-iscS-iscU-iscA-hscB-hscA-fdx-ORF3 gene cluster involved in the assembly of Fe-S clusters in Escherichia coli." Takahashi Y., Nakamura M. J. Biochem. 126:917-926(1999) [PubMed] [Europe PMC] [Abstract] Cited for: CHARACTERIZATION. Strain: C41(DE3).
[9]	"Contribution of cysteine desulfurase (NifS protein) to the biotin synthase reaction of Escherichia coli." Kiyasu T., Asakura A., Nagahashi Y., Hoshino T. J. Bacteriol. 182:2879-2885(2000) [PubMed] [Europe PMC] [Abstract] Cited for: CHARACTERIZATION. Strain: ATCC 33694 / HB101.
[10]	"The iscS gene in Escherichia coli is required for the biosynthesis of 4-thiouridine, thiamin, and NAD." Lauhon C.T., Kambampati R. J. Biol. Chem. 275:20096-20103(2000) [PubMed] [Europe PMC] [Abstract] Cited for: CHARACTERIZATION. Strain: K12 / MC1061 / ATCC 53338 / DSM 7140.
[11]	"Escherichia coli NifS-like proteins provide selenium in the pathway for the biosynthesis of selenophosphate." Lacourciere G.M., Mihara H., Kurihara T., Esaki N., Stadtman T.C. J. Biol. Chem. 275:23769-23773(2000) [PubMed] [Europe PMC] [Abstract] Cited for: FUNCTION. Strain: MBO8.
[12]	"The cysteine desulfurase, IscS, has a major role in in vivo Fe-S cluster formation in Escherichia coli." Schwartz C.J., Djaman O., Imlay J.A., Kiley P.J. Proc. Natl. Acad. Sci. U.S.A. 97:9009-9014(2000) [PubMed] [Europe PMC] [Abstract] Cited for: CHARACTERIZATION. Strain: K12 / MG1655 / ATCC 47076.
[13]	"Mechanistic insights into sulfur relay by multiple sulfur mediators involved in thiouridine biosynthesis at tRNA wobble positions." Ikeuchi Y., Shigi N., Kato J., Nishimura A., Suzuki T. Mol. Cell 21:97-108(2006) [PubMed] [Europe PMC] [Abstract] Cited for: FUNCTION, SUBUNIT.
[14]	"Crystal structure of IscS, a cysteine desulfurase from Escherichia coli." Cupp-Vickery J.R., Urbina H., Vickery L.E. J. Mol. Biol. 330:1049-1059(2003) [PubMed] [Europe PMC] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.1 ANGSTROMS), PYRIDOXAL PHOSPHATE AT LYS-206, SUBUNIT, ACTIVE SITE CYS-328.
+	Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ

U00096 Genomic DNA. Translation: AAT48142.1.
AP009048 Genomic DNA. Translation: BAA16424.1.

RefSeq

YP_026169.1. NC_000913.2.
YP_490758.1. NC_007779.1.

3D structure databases

PDBe
RCSB PDB
PDBj

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1P3W	X-ray	2.10	A/B	1-404	[»]

ProteinModelPortal

P0A6B7.

SMR

P0A6B7. Positions 1-398.

ModBase

Search...

Protein-protein interaction databases

DIP

DIP-29109N.

IntAct

P0A6B7. 43 interactions.

MINT

MINT-236550.

STRING

511145.b2530.

Proteomic databases

PaxDb

P0A6B7.

PRIDE

P0A6B7.

Protocols and materials databases

StructuralBiologyKnowledgebase

Search...

Genome annotation databases

EnsemblBacteria

AAT48142; AAT48142; b2530.
BAA16424; BAA16424; BAA16424.

GeneID

12934517.
947004.

KEGG

ecj:Y75_p2483.
eco:b2530.

PATRIC

32120457. VBIEscCol129921_2631.

Organism-specific databases

EchoBASE

EB2542.

EcoGene

EG12677. iscS.

Phylogenomic databases

eggNOG

COG1104.

HOGENOM

HOG000017510.

KO

K04487.

OMA

LWEMFKQ.

ProtClustDB

PRK14012.

Enzyme and pathway databases

BioCyc

EcoCyc:G7325-MONOMER.
ECOL316407:JW2514-MONOMER.
MetaCyc:G7325-MONOMER.

Gene expression databases

Genevestigator

P0A6B7.

Family and domain databases

Gene3D

3.40.640.10. 1 hit.
3.90.1150.10. 1 hit.

HAMAP

MF_00331. Cys_desulf_aminotr_5.

InterPro

IPR000192. Aminotrans_V/Cys_dSase.
IPR020578. Aminotrans_V_PyrdxlP_BS.
IPR010240. Cys_deSase.
IPR016454. Cysteine_dSase_NifS.
IPR015424. PyrdxlP-dep_Trfase.
IPR015421. PyrdxlP-dep_Trfase_major_sub1.
IPR015422. PyrdxlP-dep_Trfase_major_sub2.
[Graphical view]

Pfam

PF00266. Aminotran_5. 1 hit.
[Graphical view]

PIRSF

PIRSF005572. NifS. 1 hit.

SUPFAM

SSF53383. PyrdxlP-dep_Trfase_major. 1 hit.

TIGRFAMs

TIGR02006. IscS. 1 hit.

PROSITE

PS00595. AA_TRANSFER_CLASS_5. 1 hit.
[Graphical view]

ProtoNet

Search...

Other

EvolutionaryTrace

P0A6B7.

Entry information

Entry name

ISCS_ECOLI

Accession

Primary (citable) accession number: P0A6B7
Secondary accession number(s): P39171 , P76581, P76992, Q8XA86

Entry history

Integrated into UniProtKB/Swiss-Prot:	June 7, 2005
Last sequence update:	June 7, 2005
Last modified:	May 1, 2013
This is version 80 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Prokaryotic Protein Annotation Program