DB code: M00164

CATH domain -.-.-.- :
2.40.30.10 : Elongation Factor Tu (Ef-tu); domain 3
1.20.990.10 : NADPH-cytochrome p450 Reductase; Chain A, domain 3
3.40.50.80 : Rossmann fold
-.-.-.- :
3.30.413.10 : Sulfite Reductase Hemoprotein; domain 1 Catalytic domain
3.90.480.10 : Sulfite Reductase Hemoprotein; domain 2 Catalytic domain
3.30.413.10 : Sulfite Reductase Hemoprotein; domain 1 Catalytic domain
E.C. 1.8.1.2
CSA 1aop
M-CSA 1aop
MACiE

CATH domain Related DB codes (homologues)
1.20.990.10 : NADPH-cytochrome p450 Reductase; Chain A, domain 3 M00006
2.40.30.10 : Elongation Factor Tu (Ef-tu); domain 3 D00043 M00006 M00141 M00159
3.40.50.80 : Rossmann fold D00043 M00006 M00141 M00159

Uniprot Enzyme Name
UniprotKB Protein name Synonyms RefSeq Pfam
P38038 Sulfite reductase [NADPH] flavoprotein alpha-component
SIR-FP
EC 1.8.1.2
NP_417244.1 (Protein)
NC_000913.2 (DNA/RNA sequence)
YP_490973.1 (Protein)
NC_007779.1 (DNA/RNA sequence)
PF00667 (FAD_binding_1)
PF00258 (Flavodoxin_1)
PF00175 (NAD_binding_1)
[Graphical View]
P17846 Sulfite reductase [NADPH] hemoprotein beta-component
SIR-HP
SIRHP
EC 1.8.1.2
NP_417243.1 (Protein)
NC_000913.2 (DNA/RNA sequence)
YP_490972.1 (Protein)
NC_007779.1 (DNA/RNA sequence)
PF01077 (NIR_SIR)
PF03460 (NIR_SIR_ferr)
[Graphical View]

KEGG enzyme name
sulfite reductase (NADPH)
sulfite (reduced nicotinamide adenine dinucleotide phosphate)reductase
NADPH-sulfite reductase
NADPH-dependent sulfite reductase
H2S-NADP oxidoreductase
sulfite reductase (NADPH2)

UniprotKB: Accession Number Entry name Activity Subunit Subcellular location Cofactor
P38038 CYSJ_ECOLI H(2)S + 3 NADP(+) + 3 H(2)O = sulfite + 3 NADPH. Alpha(8)-beta(8). The alpha component is a flavoprotein, the beta component is a hemoprotein. Binds 1 FAD per subunit. Binds 1 FMN per subunit.
P17846 CYSI_ECOLI H(2)S + 3 NADP(+) + 3 H(2)O = sulfite + 3 NADPH. Alpha(8)-beta(4). The alpha component is a flavoprotein, the beta component is a hemoprotein. Binds 1 siroheme per subunit. Binds 1 4Fe-4S cluster per subunit.

KEGG Pathways
Map code Pathways E.C.
MAP00920 Sulfur metabolism

Compound table
Cofactors Substrates Products Intermediates
KEGG-id L00024 C00748 C00016 C00061 C00094 C00005 C00080 C00283 C00006 C00001
E.C.
Compound [4Fe-4S] Siroheme FAD FMN Sulfite NADPH H+ Hydrogen sulfide NADP+ H2O
Type heavy metal,sulfide group aromatic ring (with nitrogen atoms),carboxyl group,heavy metal amide group,amine group,aromatic ring (only carbon atom),aromatic ring (with nitrogen atoms),carbohydrate,nucleotide amide group,amine group,aromatic ring (only carbon atom),aromatic ring (with nitrogen atoms),carbohydrate,phosphate group/phosphate ion sulfite amide group,amine group,nucleotide others sulfhydryl group amide group,amine group,nucleotide H2O
ChEBI 33725
33725
28599
28599
16238
16238
17621
17621
48854
48854
16474
16474
15378
15378
16136
16136
18009
18009
15377
15377
PubChem 25199933
439303
5460009
9548568
25199933
439303
5460009
9548568
643975
643975
643976
643976
1100
22132154
1100
22132154
5884
5884
1038
1038
18779926
402
18779926
402
5886
5886
22247451
962
22247451
962
1ddgA01 Unbound Unbound Bound:FAD Unbound Unbound Unbound Unbound Unbound Unbound
1ddgB01 Unbound Unbound Bound:FAD Unbound Unbound Unbound Unbound Unbound Unbound
1ddiA01 Unbound Unbound Bound:FAD Unbound Unbound Unbound Unbound Unbound Unbound
1ddgA02 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound
1ddgB02 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound
1ddiA02 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound
1ddgA03 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound
1ddgB03 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound
1ddiA03 Unbound Unbound Unbound Unbound Unbound Bound:NAP Unbound Unbound Unbound
1aopA01 Unbound Unbound Unbound Unbound Analogue:PO4 Unbound Unbound Unbound Unbound
1geoA01 Unbound Unbound Unbound Unbound Analogue:PO4 Unbound Unbound Unbound Unbound
1gepA01 Unbound Unbound Unbound Unbound Bound:SO3 Unbound Unbound Unbound Unbound
2aopA01 Unbound Unbound Unbound Unbound Analogue:PO4 Unbound Unbound Unbound Unbound
2gepA01 Unbound Unbound Unbound Unbound Bound:SO3 Unbound Unbound Unbound Unbound
3aopA01 Unbound Unbound Unbound Unbound Analogue:PO4 Unbound Unbound Unbound Unbound
3geoA01 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Intermediate-bound:NO2
4aopA01 Unbound Unbound Unbound Unbound Analogue:PO4 Unbound Unbound Unbound Unbound
4gepA01 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Intermediate-analogue:CYN
5aopA01 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound
5gepA01 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Intermediate-analogue:CMO
6gepA01 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Intermediate-analogue:_NO
7gepA01 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Intermediate-bound:_SX
8gepA01 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound
1aopA02 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound
1geoA02 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound
1gepA02 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound
2aopA02 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound
2gepA02 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound
3aopA02 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound
3geoA02 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound
4aopA02 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound
4gepA02 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound
5aopA02 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound
5gepA02 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound
6gepA02 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound
7gepA02 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound
8gepA02 Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound Unbound
1aopA03 Bound:SF4 Bound:SRM-PO4 Unbound Unbound Unbound Unbound Unbound Unbound Unbound
1geoA03 Bound:FS4 Bound:SRM-PO4 Unbound Unbound Unbound Unbound Unbound Unbound Unbound
1gepA03 Bound:FS4 Bound:SRM-SO3 Unbound Unbound Unbound Unbound Unbound Unbound Unbound
2aopA03 Bound:SF4 Bound:SRM-PO4 Unbound Unbound Unbound Unbound Unbound Unbound Unbound
2gepA03 Bound:SF4 Bound:SRM-SO3 Unbound Unbound Unbound Unbound Unbound Unbound Unbound
3aopA03 Bound:SF4 Bound:SRM-PO4 Unbound Unbound Unbound Unbound Unbound Unbound Unbound
3geoA03 Bound:SF4 Bound:SRM-NO2 Unbound Unbound Unbound Unbound Unbound Unbound Unbound
4aopA03 Bound:SF4 Bound:SRM-PO4 Unbound Unbound Unbound Unbound Unbound Unbound Unbound
4gepA03 Bound:SF4 Bound:SRM-CYN Unbound Unbound Unbound Unbound Unbound Unbound Unbound
5aopA03 Bound:SF4 Bound:SRM Unbound Unbound Unbound Unbound Unbound Unbound Unbound
5gepA03 Bound:SF4 Bound:SRM-CMO Unbound Unbound Unbound Unbound Unbound Unbound Unbound
6gepA03 Bound:SF4 Bound:SRM-_NO Unbound Unbound Unbound Unbound Unbound Unbound Unbound
7gepA03 Bound:SF4 Bound:SRM-_SX Unbound Unbound Unbound Unbound Unbound Unbound Unbound
8gepA03 Bound:SF4 Bound:SRM Unbound Unbound Unbound Unbound Unbound Unbound Unbound

Reference for Active-site residues
resource references E.C.
Swiss-prot;P17846 & PDB;1aop & literature [14], [15]

Active-site residues
PDB Catalytic residues Cofactor-binding residues Modified residues Main-chain involved in catalysis Comment
1ddgA01
1ddgB01
1ddiA01
1ddgA02
1ddgB02
1ddiA02
1ddgA03
1ddgB03
1ddiA03
1aopA01 ARG 153;LYS 215;LYS 217
1geoA01 ARG 153;LYS 215;LYS 217
1gepA01 ARG 153;LYS 215;LYS 217
2aopA01 ARG 153;LYS 215;LYS 217
2gepA01 ARG 153;LYS 215;LYS 217
3aopA01 ARG 153;LYS 215;LYS 217
3geoA01 ARG 153;LYS 215;LYS 217
4aopA01 ARG 153;LYS 215;LYS 217
4gepA01 ARG 153;LYS 215;LYS 217
5aopA01 ARG 153;LYS 215;LYS 217
5gepA01 ARG 153;LYS 215;LYS 217
6gepA01 ARG 153;LYS 215;LYS 217
7gepA01 ARG 153;LYS 215;LYS 217
8gepA01 ARG 153;LYS 215;LYS 217
1aopA02 ARG 83
1geoA02 ARG 83
1gepA02 ARG 83
2aopA02 ARG 83
2gepA02 ARG 83
3aopA02 ARG 83
3geoA02 ARG 83
4aopA02 ARG 83
4gepA02 ARG 83
5aopA02 ARG 83
5gepA02 ARG 83
6gepA02 ARG 83
7gepA02 ARG 83
8gepA02 ARG 83
1aopA03 CYS 434;CYS 440;CYS 479;CYS 483(4Fe-4S binding);CYS 483(Siroheme binding)
1geoA03 CYS 434;CYS 440;CYS 479;CYS 483(4Fe-4S binding);CYS 483(Siroheme binding)
1gepA03 CYS 434;CYS 440;CYS 479;CYS 483(4Fe-4S binding);CYS 483(Siroheme binding)
2aopA03 CYS 434;CYS 440;CYS 479;CYS 483(4Fe-4S binding);CYS 483(Siroheme binding)
2gepA03 CYS 434;CYS 440;CYS 479;CYS 483(4Fe-4S binding);CYS 483(Siroheme binding)
3aopA03 CYS 434;CYS 440;CYS 479;CYS 483(4Fe-4S binding);CYS 483(Siroheme binding)
3geoA03 CYS 434;CYS 440;CYS 479;CYS 483(4Fe-4S binding);CYS 483(Siroheme binding)
4aopA03 CYS 434;CYS 440;CYS 479;CYS 483(4Fe-4S binding);CYS 483(Siroheme binding)
4gepA03 CYS 434;CYS 440;CYS 479;CYS 483(4Fe-4S binding);CYS 483(Siroheme binding)
5aopA03 CYS 434;CYS 440;CYS 479;CYS 483(4Fe-4S binding);CYS 483(Siroheme binding)
5gepA03 CYS 434;CYS 440;CYS 479;CYS 483(4Fe-4S binding);CYS 483(Siroheme binding)
6gepA03 CYS 434;CYS 440;CYS 479;CYS 483(4Fe-4S binding);CYS 483(Siroheme binding)
7gepA03 CYS 434;CYS 440;CYS 479;CYS 483(4Fe-4S binding);CYS 483(Siroheme binding)
8gepA03 CYS 434;CYS 440;CYS 479;CYS 483(4Fe-4S binding);CYS 483(Siroheme binding)

References for Catalytic Mechanism
References Sections No. of steps in catalysis
[5]
Scheme 1, p.15805-15806
[8]
p.18607-18608
[9]
p.64-66
[12]
Scheme 1, p.20554-20555
[13]
[14]
p.12114-12118
[15]
Fig.13, 12133-12126
[17]
Scheme 2, Scheme 3, p.6120-6122
[18]
Scheme 1
[21]
[22]

References
[1]
Resource
Comments
Medline ID
PubMed ID 6281269
Journal J Biol Chem
Year 1982
Volume 257
Pages 6343-50
Authors Siegel LM, Rueger DC, Barber MJ, Krueger RJ, Orme-Johnson NR, Orme-Johnson WH
Title Escherichia coli sulfite reductase hemoprotein subunit. Prosthetic groups, catalytic parameters, and ligand complexes.
Related PDB
Related UniProtKB
[2]
Resource
Comments
Medline ID
PubMed ID 3525540
Journal J Biol Chem
Year 1986
Volume 261
Pages 10277-81
Authors McRee DE, Richardson DC, Richardson JS, Siegel LM
Title The heme and Fe4S4 cluster in the crystallographic structure of Escherichia coli sulfite reductase.
Related PDB
Related UniProtKB
[3]
Resource
Comments
Medline ID
PubMed ID 3056517
Journal Biochemistry
Year 1988
Volume 27
Pages 5984-90
Authors Young LJ, Siegel LM
Title Superoxidized states of Escherichia coli sulfite reductase heme protein subunit.
Related PDB
Related UniProtKB
[4]
Resource
Comments
Medline ID
PubMed ID 2670946
Journal J Biol Chem
Year 1989
Volume 264
Pages 15726-37
Authors Ostrowski J, Wu JY, Rueger DC, Miller BE, Siegel LM, Kredich NM
Title Characterization of the cysJIH regions of Salmonella typhimurium and Escherichia coli B. DNA sequences of cysI and cysH and a model for the siroheme-Fe4S4 active center of sulfite reductase hemoprotein based on amino acid homology with spinach nitrite reductase.
Related PDB
Related UniProtKB
[5]
Resource
Comments
Medline ID
PubMed ID 2550423
Journal J Biol Chem
Year 1989
Volume 264
Pages 15796-808
Authors Ostrowski J, Barber MJ, Rueger DC, Miller BE, Siegel LM, Kredich NM
Title Characterization of the flavoprotein moieties of NADPH-sulfite reductase from Salmonella typhimurium and Escherichia coli. Physicochemical and catalytic properties, amino acid sequence deduced from DNA sequence of cysJ, and comparison with NADPH-cytochrome P-450 reductase.
Related PDB
Related UniProtKB
[6]
Resource
Comments
Medline ID
PubMed ID 8457551
Journal Biochemistry
Year 1993
Volume 32
Pages 2853-67
Authors Kaufman J, Spicer LD, Siegel LM
Title Proton NMR of Escherichia coli sulfite reductase: the unligated hemeprotein subunit.
Related PDB
Related UniProtKB
[7]
Resource
Comments
Medline ID
PubMed ID 8395881
Journal Biochemistry
Year 1993
Volume 32
Pages 8782-91
Authors Kaufman J, Siegel LM, Spicer LD
Title Proton NMR of Escherichia coli sulfite reductase: studies of the heme protein subunit with added ligands.
Related PDB
Related UniProtKB
[8]
Resource
Comments
Medline ID
PubMed ID 8360156
Journal J Biol Chem
Year 1993
Volume 268
Pages 18604-9
Authors Coves J, Niviere V, Eschenbrenner M, Fontecave M
Title NADPH-sulfite reductase from Escherichia coli. A flavin reductase participating in the generation of the free radical of ribonucleotide reductase.
Related PDB
Related UniProtKB
[9]
Resource
Comments
Medline ID
PubMed ID 7928966
Journal J Bacteriol
Year 1994
Volume 176
Pages 6050-8
Authors Hansen J, Cherest H, Kielland-Brandt MC
Title Two divergent MET10 genes, one from Saccharomyces cerevisiae and one from Saccharomyces carlsbergensis, encode the alpha subunit of sulfite reductase and specify potential binding sites for FAD and NADPH.
Related PDB
Related UniProtKB
[10]
Resource
Comments X-RAY CRYSTALLOGRAPHY (1.6 ANGSTROMS)
Medline ID 96008578
PubMed ID 7569952
Journal Science
Year 1995
Volume 270
Pages 59-67
Authors Crane BR, Siegel LM, Getzoff ED
Title Sulfite reductase structure at 1.6 A: evolution and catalysis for reduction of inorganic anions.
Related PDB 1aop 1geo 1gep
Related UniProtKB P17846
[11]
Resource
Comments CHARACTERIZATION OF FAD AND FMN DOMAINS.
Medline ID 96049560
PubMed ID 7589518
Journal FEBS Lett
Year 1995
Volume 374
Pages 82-4
Authors Eschenbrenner M, Coves J, Fontecave M
Title NADPH-sulfite reductase flavoprotein from Escherichia coli: contribution to the flavin content and subunit interaction.
Related PDB
Related UniProtKB P38038
[12]
Resource
Comments CHARACTERIZATION AS A NADPH:FLAVIN OXIDOREDUCTASE.
Medline ID 95386502
PubMed ID 7657631
Journal J Biol Chem
Year 1995
Volume 270
Pages 20550-5
Authors Eschenbrenner M, Coves J, Fontecave M
Title The flavin reductase activity of the flavoprotein component of sulfite reductase from Escherichia coli. A new model for the protein structure.
Related PDB
Related UniProtKB P38038
[13]
Resource
Comments CHARACTERIZATION OF FMN DOMAIN 1-219.
Medline ID 97297802
PubMed ID 9153434
Journal Biochemistry
Year 1997
Volume 36
Pages 5921-8
Authors Coves J, Zeghouf M, Macherel D, Guigliarelli B, Asso M, Fontecave M
Title Flavin mononucleotide-binding domain of the flavoprotein component of the sulfite reductase from Escherichia coli.
Related PDB
Related UniProtKB P38038
[14]
Resource
Comments X-RAY CRYSTALLOGRAPHY (1.75 ANGSTROMS)
Medline ID 97461529
PubMed ID 9315848
Journal Biochemistry
Year 1997
Volume 36
Pages 12101-19
Authors Crane BR, Siegel LM, Getzoff ED
Title Structures of the siroheme- and Fe4S4-containing active center of sulfite reductase in different states of oxidation: heme activation via reduction-gated exogenous ligand exchange.
Related PDB 2aop 2gep 3aop 3geo 4aop 4gep 5aop 5gep 6gep 7gep 8gep
Related UniProtKB P17846
[15]
Resource
Comments
Medline ID
PubMed ID 9315849
Journal Biochemistry
Year 1997
Volume 36
Pages 12120-37
Authors Crane BR, Siegel LM, Getzoff ED
Title Probing the catalytic mechanism of sulfite reductase by X-ray crystallography: structures of the Escherichia coli hemoprotein in complex with substrates, inhibitors, intermediates, and products.
Related PDB
Related UniProtKB
[16]
Resource
Comments CHARACTERIZATION AS A NADPH-CYTOCHROME P450 REDUCTASE.
Medline ID 98289576
PubMed ID 9618257
Journal Biochem Biophys Res Commun
Year 1998
Volume 246
Pages 602-5
Authors Zeghouf M, Defaye G, Fontecave M, Coves J
Title The flavoprotein component of the Escherichia coli sulfite reductase can act as a cytochrome P450c17 reductase.
Related PDB
Related UniProtKB P38038
[17]
Resource
Comments CHARACTERIZATION.
Medline ID 98226652
PubMed ID 9558350
Journal Biochemistry
Year 1998
Volume 37
Pages 6114-23
Authors Zeghouf M, Fontecave M, Macherel D, Coves J
Title The flavoprotein component of the Escherichia coli sulfite reductase: expression, purification, and spectral and catalytic properties of a monomeric form containing both the flavin adenine dinucleotide and the flavin mononucleotide cofactors.
Related PDB
Related UniProtKB P38038
[18]
Resource
Comments CHARACTERIZATION OF FAD DOMAIN.
Medline ID 99386679
PubMed ID 10455035
Journal Biochem J
Year 1999
Volume 342
Pages 465-72
Authors Coves J, Lebrun C, Gervasi G, Dalbon P, Fontecave M
Title Overexpression of the FAD-binding domain of the sulphite reductase flavoprotein component from Escherichia coli and its inhibition by iodonium diphenyl chloride.
Related PDB
Related UniProtKB P38038
[19]
Resource
Comments
Medline ID
PubMed ID 10215853
Journal Eur J Biochem
Year 1999
Volume 261
Pages 430-7
Authors Evrard A, Zeghouf M, Fontecave M, Roby C, Coves J
Title 31P nuclear magnetic resonance study of the flavoprotein component of the Escherichia coli sulfite reductase.
Related PDB
Related UniProtKB
[20]
Resource
Comments QUATERNARY STRUCTURE.
Medline ID 20545508
PubMed ID 10984484
Journal J Biol Chem
Year 2000
Volume 275
Pages 37651-6
Authors Zeghouf M, Fontecave M, Coves J
Title A simplifed functional version of the Escherichia coli sulfite reductase.
Related PDB
Related UniProtKB P38038
[21]
Resource
Comments X-RAY CRYSTALLOGRAPHY (2.01 ANGSTROMS) OF 225-598.
Medline ID 20328609
PubMed ID 10860732
Journal J Mol Biol
Year 2000
Volume 299
Pages 199-212
Authors Gruez A, Pignol D, Zeghouf M, Coves J, Fontecave M, Ferrer JL, Fontecilla-Camps JC
Title Four crystal structures of the 60 kDa flavoprotein monomer of the sulfite reductase indicate a disordered flavodoxin-like module.
Related PDB 1ddi 1ddg
Related UniProtKB P38038
[22]
Resource
Comments CHARACTERIZATION AND STRUCTURE BY NMR OF 52-219.
Medline ID 21885835
PubMed ID 11888295
Journal Biochemistry
Year 2002
Volume 41
Pages 3770-80
Authors Champier L, Sibille N, Bersch B, Brutscher B, Blackledge M, Coves J
Title Reactivity, secondary structure, and molecular topology of the Escherichia coli sulfite reductase flavodoxin-like domain.
Related PDB
Related UniProtKB P38038

Comments
This enzyme is made of two subunits, alpha subunit (Swiss-prot;P38038) and beta subunit (Swiss-prot;P17846). The alpha subunit is composed of N-terminal FMN-binding domain, FAD-binding domain, Ferredoxin NADP+ reductase-like module, and C-terminal NADPH-binding domain. As the N-terminal domain is flexible relative to the other domains, its structure has not been determined (see [20]).
In contrast, the beta subunit is composed of N-terminal domain, two active-site domains, and C-terminal Sirohem- and Iron/sulfur-binding domain.
According to the literature [5], [12] & [18], electrons are transferred from NADPH at the alpha subunit, through FAD and FMN, to sulfite at the beta subunit.

Created Updated
2004-03-25 2009-02-26