Protein target profile

KP13_02396

Sulfite reductase [NADPH] flavoprotein alpha-component

Genome: KpKP13 Gene: AHE42967.1 cysJ 3D evidence: AlphaFold DB model + ColabFold model UniProt A0A0H3GWU1
Length 590
Pocket druggability 0.412
Direct ligand evidence 0 59 total records
Functional annotation 1 EC 8 GO
Target summary

Target candidate with partial support; inspect missing evidence before prioritizing.

Automated synthesis of the evidence currently loaded. Review the underlying records before prioritizing this protein.

Terms and data sources used on this page

PDB: experimentally determined structures from the Protein Data Bank. These are the strongest structural evidence, but may cover only part of the protein.

AlphaFold DB model: a precomputed predicted structure downloaded from AlphaFold Database/UniProt, not an experiment performed here.

ColabFold model: a predicted structure generated for this workspace; interpret it with coverage and confidence.

pLDDT: confidence score for predicted structures. High values support local geometry; low values mean the region should not drive pocket interpretation.

FPocket / P2Rank: software tools that predict possible ligand-binding pockets on a 3D structure. They are useful screening signals, not experimental validation.

Druggability: a pocket-based estimate of whether a small molecule could bind productively. It does not mean a drug already exists.

PDB ligand: a compound observed in an experimental structure. Direct same-protein records are stronger than homolog-transferred records.

ChEMBL: a public database of measured compound bioactivity. Direct entries are stronger than entries transferred from similar proteins.

ZINC: a purchasable-compound database. Here it marks proposed candidates from chemical similarity, not measured binders.

LigQ / LigQ_2: an internal Target pipeline step that gathers PDB, ChEMBL, and ZINC ligand evidence for each protein.

Off-target: sequence similarity to proteins we prefer not to hit, such as human proteins or beneficial gut microbiome proteins.

DEG: Database of Essential Genes. A match suggests the protein resembles genes known to be essential in other organisms.

Roary / CoreCruncher: pan-genome tools used to decide whether a gene is core across analyzed strains or accessory/strain-specific.

EC / GO: functional annotations: EC describes enzyme reactions; GO describes biological process, molecular function, or cellular component.

KEGG pathway: a curated metabolic route label used here to group reactions imported from the metabolic model.

Chokepoint: a metabolic reaction that is the only producer or consumer of a metabolite in the imported model.

Prioritization evidence

Selectivity, essentiality, structural confidence, conservation, and predicted binding-site evidence.

Off-target risk

Human off-target
Hit
Human identity (%)
34.568 Lower values reduce human off-target concern.
Human E-value
1.3699999999999998e-60
Gut microbiome similarity
2.7% of screened genomes Lower prevalence suggests narrower overlap with the screened gut microbiome.

Essentiality

Essential (DEG)
N
DEG identity (%)
0.0 Higher values support similarity to known essential genes.

Localization

Localization
CytoplasmicMembrane

Structure confidence

ColabFold pLDDT
91.57 0-100 confidence; >70 supports local structural interpretation.

Binding-site evidence

AlphaFold DB / UniProt model

The selected pocket score is the FPocket value used for ranking after applying the curated structure priority. It estimates small-molecule pocket quality; it is not experimental binding evidence. The 3D viewer may show a different loaded structure, so visible pockets can differ.

FPocket 0.412
Structure A0A0H3GWU1
Pocket Pocket 18
P2Rank 0.614
Structure A0A0H3GWU1
Pocket Pocket 1
ColabFold model
FPocket 0.299 · Pocket 34
P2Rank 0.541 · Pocket 1
Core conservation Accessory gene
Roary core
CoreCruncher accessory
Gut microbiome 128 / 4744 genomes with a hit
Prevalence 2.7%

Cross-references

External database identifiers for this protein, its structures, ligands, and metabolic reactions.

Sequence

Primary amino-acid sequence viewer.

MLPLNPEQLARLQAATTDFTPTQLAWVSGYFWGVLNQQSGAAVAAPAPAAEVPTITLISASQTGNARRVAEALRDDLLAAKLNVKLVNAGDYKFKQIAAEKLLVVVTSTQGEGEPPEEAVALHKFLFSKKAPKLDGTAFAVFGLGDTSYEFFCQSGKDFDNKLAELGAERLLDRVDADVEYQAAAAEWRARVVEALKARAPVAAPAQLATSGAVNDIHTSPYTKEAPLTATLSVNQKITGRNSEKDVRHIEIDLGDSGLRYQPGDALGVWYQNDPQLVKELVELLWLKGDEPVTVEGKTLPLSEALQWHFELTVNTATIVENYATLTRSESLLPLVGDKAQLQQYAAATPIVDMVRFSPAQLDAEALIGLLRPLTPRLYSIASSQAEVESEVHVTVGVVRYEIEGRARAGGASSFLADRVEEDGEVRVFIEHNDNFRLPANPETPVIMIGPGTGIAPFRAFMQQRAADGAQGKNWLFFGNPHFTEDFLYQVEWQSYVKEGLLTRIDLAWSRDQQQKIYVQDKLREQGAELWRWITDGAHIYVCGDANRMAKDVENTLLEVIAEYGAMDAEAADEFLSELRVERRYQRDVY

Functional annotations

Enzyme classification and Gene Ontology terms linked to this protein.

1 EC 8 GO

Enzyme Commission (EC)

1

Gene Ontology (GO)

8
  • GO:0004783 Catalysis of the reaction: hydrogen sulfide + 3 NADP+ + 3 H2O = sulfite + 3 NADPH + 3 H+.
  • GO:0010181 Binding to flavin mono nucleotide. Flavin mono nucleotide (FMN) is the coenzyme or the prosthetic group of various flavoprotein oxidoreductase enzymes.
  • GO:0019344 The chemical reactions and pathways resulting in the formation of L-cysteine, 2-amino-3-mercaptopropanoic acid.
  • GO:0016491 Catalysis of an oxidation-reduction (redox) reaction, a reversible chemical reaction in which the oxidation state of an atom or atoms within a molecule is altered. One substrate acts as a hydrogen or electron donor and becomes oxidized, while the other acts as hydrogen or electron acceptor and becomes reduced.
  • GO:0050660 Binding to FAD, flavin-adenine dinucleotide, the coenzyme or the prosthetic group of various flavoprotein oxidoreductase enzymes, in either the oxidized form, FAD, or the reduced form, FADH2.
  • GO:0000103 The pathways by which inorganic sulfate is processed and incorporated into sulfated compounds.
  • GO:0005829 The part of the cytoplasm that does not contain organelles but which does contain other particulate matter, such as protein complexes.
  • GO:0070814 The chemical reactions and pathways resulting in the formation of hydrogen sulfide, H2S.

Sequence domains and features

Domain and signature matches imported from InterPro and related databases.

58 records
Show feature table
Start End DB Term Name
1 590 Hamap MF_01541 Sulfite reductase [NADPH] flavoprotein alpha-component [cysJ].
1 590 InterPro IPR029758 Sulphite reductase [NADPH] flavoprotein, alpha chain, Proteobacteria
271 375 Gene3D G3DSA:1.20.990.10 -
271 375 InterPro IPR023173 NADPH-cytochrome p450 reductase, FAD-binding, alpha-helical domain superfamily
51 585 PANTHER PTHR19384 NITRIC OXIDE SYNTHASE-RELATED
45 210 FunFam G3DSA:3.40.50.360:FF:000018 Sulfite reductase [NADPH] flavoprotein alpha-component
221 415 Pfam PF00667 FAD binding domain
221 415 InterPro IPR003097 Sulfite reductase [NADPH] flavoprotein alpha-component-like, FAD-binding
2 590 NCBIfam TIGR01931 assimilatory sulfite reductase (NADPH) flavoprotein subunit
2 590 InterPro IPR010199 Sulphite reductase [NADPH] flavoprotein, alpha chain
231 590 CDD cd06199 SiR
54 200 SUPERFAMILY SSF52218 Flavoproteins
54 200 InterPro IPR029039 Flavoprotein-like superfamily
438 590 FunFam G3DSA:3.40.50.80:FF:000001 NADPH--cytochrome P450 reductase 1
539 547 PRINTS PR00371 Flavoprotein pyridine nucleotide cytochrome reductase signature
539 547 InterPro IPR001709 Flavoprotein pyridine nucleotide cytochrome reductase
410 419 PRINTS PR00371 Flavoprotein pyridine nucleotide cytochrome reductase signature
410 419 InterPro IPR001709 Flavoprotein pyridine nucleotide cytochrome reductase
447 466 PRINTS PR00371 Flavoprotein pyridine nucleotide cytochrome reductase signature
447 466 InterPro IPR001709 Flavoprotein pyridine nucleotide cytochrome reductase
472 481 PRINTS PR00371 Flavoprotein pyridine nucleotide cytochrome reductase signature
472 481 InterPro IPR001709 Flavoprotein pyridine nucleotide cytochrome reductase
485 496 PRINTS PR00371 Flavoprotein pyridine nucleotide cytochrome reductase signature
485 496 InterPro IPR001709 Flavoprotein pyridine nucleotide cytochrome reductase
261 271 PRINTS PR00371 Flavoprotein pyridine nucleotide cytochrome reductase signature
261 271 InterPro IPR001709 Flavoprotein pyridine nucleotide cytochrome reductase
516 532 PRINTS PR00371 Flavoprotein pyridine nucleotide cytochrome reductase signature
516 532 InterPro IPR001709 Flavoprotein pyridine nucleotide cytochrome reductase
377 384 PRINTS PR00371 Flavoprotein pyridine nucleotide cytochrome reductase signature
377 384 InterPro IPR001709 Flavoprotein pyridine nucleotide cytochrome reductase
271 375 FunFam G3DSA:1.20.990.10:FF:000004 Sulfite reductase [NADPH] flavoprotein alpha-component
58 186 Pfam PF00258 Flavodoxin
58 186 InterPro IPR008254 Flavodoxin/nitric oxide synthase
225 439 ProSiteProfiles PS51384 Ferredoxin reductase-type FAD binding domain profile.
225 439 InterPro IPR017927 FAD-binding domain, ferredoxin reductase-type
448 554 Pfam PF00175 Oxidoreductase NAD-binding domain
448 554 InterPro IPR001433 Oxidoreductase FAD/NAD(P)-binding
435 590 SUPERFAMILY SSF52343 Ferredoxin reductase-like, C-terminal NADP-linked domain
435 590 InterPro IPR039261 Ferredoxin-NADP reductase (FNR), nucleotide-binding domain
55 193 ProSiteProfiles PS50902 Flavodoxin-like domain profile.
55 193 InterPro IPR008254 Flavodoxin/nitric oxide synthase
44 210 Gene3D G3DSA:3.40.50.360 -
44 210 InterPro IPR029039 Flavoprotein-like superfamily
436 590 Gene3D G3DSA:3.40.50.80 -
436 590 InterPro IPR039261 Ferredoxin-NADP reductase (FNR), nucleotide-binding domain
1 590 PIRSF PIRSF000207 SiR-FP_CysJ
1 590 InterPro IPR010199 Sulphite reductase [NADPH] flavoprotein, alpha chain
218 437 SUPERFAMILY SSF63380 Riboflavin synthase domain-like
218 437 InterPro IPR017938 Riboflavin synthase-like beta-barrel
224 430 Gene3D G3DSA:2.40.30.10 Translation factors
160 179 PRINTS PR00369 Flavodoxin signature
160 179 InterPro IPR001094 Flavodoxin-like
56 69 PRINTS PR00369 Flavodoxin signature
56 69 InterPro IPR001094 Flavodoxin-like
104 115 PRINTS PR00369 Flavodoxin signature
104 115 InterPro IPR001094 Flavodoxin-like
136 146 PRINTS PR00369 Flavodoxin signature
136 146 InterPro IPR001094 Flavodoxin-like

3D structure

Selected loaded structure. Experimental PDB entries may cover only a portion of the sequence; AlphaFold DB and ColabFold models typically cover the full protein but remain computational predictions.

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Pocket score High Medium Low
How colors and pocket overlays are used
Uniform protein color marks the displayed model as a single molecular object.
Experimental PDB structures may be colored by chain to distinguish subunits or copies present in the file.
Pocket colors and alpha spheres are evidence overlays for predicted binding cavities; they are not alternative protein chains.
'Alpha spheres' is FPocket's own cavity-shape geometry, imported when available and aligned with the loaded structure.
'Pocket atoms'/'Predicted site atoms' show the pocket's residue atoms instead: P2Rank reports residues rather than alpha spheres, and FPocket falls back to this when alpha-sphere geometry is unavailable or doesn't align.
'No pocket geometry' means neither alpha spheres nor residue-position data could be found for that pocket; the layer just highlights the same residues as 'Nearby residues'.
Pocket details Inspect a specific pocket, or open the full viewer

Binding pockets · FPocket

Druggability: high ≥ 0.7 · medium 0.4–0.69 · low < 0.4

Site 1 FPocket #18
0.412
Unusual size
Show in viewer
Surrounding area

Binding pockets · P2Rank

Probability: high ≥ 0.5 · medium 0.2–0.49 · low < 0.2

Site 1 P2Rank #1
0.614
Show in viewer
Surrounding area
Site 2 P2Rank #2
0.442
Show in viewer
Surrounding area
Site 3 P2Rank #3
0.165
Show in viewer
Surrounding area
Site 4 P2Rank #4
0.136
Show in viewer
Surrounding area
Site 5 P2Rank #5
0.106
Show in viewer
Surrounding area
Residue sets
UniProt: Binding site:108-111
UniProt: Binding site:144-153
UniProt: Binding site:313-313
UniProt: Binding site:347-347
UniProt: Binding site:377-380
UniProt: Binding site:395-397
UniProt: Binding site:401-401
UniProt: Binding site:410-413
UniProt: Binding site:510-511
UniProt: Binding site:516-520
UniProt: Binding site:552-552
UniProt: Binding site:590-590
UniProt: Binding site:61-66
All structural evidence 0 experimental · 2 predicted

Structural evidence

0 + 2

Experimental PDB entries plus predicted AlphaFold DB or ColabFold models. Click Switch to display a different loaded structure in the viewer.

Entry Method Resolution Chain Coverage Links Status
AlphaFold DB AF_A0A0H3GWU1
AlphaFold DB full sequence Viewing
ColabFold KP13_02396
ColabFold full sequence Loaded

Ligand evidence

Ligands grouped by evidence source. PDB ligands keep the source crystal visible, and loaded crystals can be opened directly in the structure viewer.

59 records
Chemistry signal

Structural ligand evidence is available for this target.

Direct evidence 0 same-protein records
Transferred evidence 9 records from similar proteins
Structural ligands 9 0 loaded crystals
Measured bioactivity 0 direct and transferred ChEMBL records
Proposed compounds 50 similarity-based ZINC candidates
Best available ligand signal
2AM PDB via homolog 347.2 Da · LogP -1.86 · TPSA 186.1 Open detail RCSB PDB
A2P PDB via homolog Detail RCSB PDB
CXS PDB via homolog Detail RCSB PDB
EN6 PDB via homolog Detail RCSB PDB
FDA PDB via homolog Detail RCSB PDB

Structural evidence inferred from similar proteins. The source crystal indicates where the ligand was observed; the UniProt column identifies the homologous protein carrying that ligand.

Show only:
Ligand Source crystal UniProt (homolog) MW · LogP · TPSA Lipinski PAINS SMILES
2AM RCSB PDB P00388 347.2 Da LogP -1.86 TPSA 186.1 ✓ Ro5 ✓ Clean c1nc(c2c(n1)n(cn2)[C@H]3[C@@H]([C@@H]([C@H](O3)…
A2P RCSB PDB P00455 427.2 Da LogP -1.75 TPSA 232.6 2 viol. ✓ Clean c1nc(c2c(n1)n(cn2)[C@H]3[C@@H]([C@@H]([C@H](O3)…
CXS RCSB PDB W8SX42 221.3 Da LogP 1.19 TPSA 66.4 ✓ Ro5 ✓ Clean C1CCC(CC1)NCCCS(=O)(=O)O
EN6 RCSB PDB P00323 489.5 Da LogP 4.22 TPSA 87.4 ✓ Ro5 ✓ Clean Cc1c(c(n(n1)c2cccc3c2sc(c3)Cc4cccc(c4)C(F)(F)F)…
FDA RCSB PDB B4G043 787.6 Da LogP -1.75 TPSA 363.3 3 viol. ✓ Clean Cc1cc2c(cc1C)N(C3=C(N2)C(=O)NC(=O)N3)C[C@@H]([C…
FLC RCSB PDB P00323 189.1 Da LogP -5.25 TPSA 140.6 ✓ Ro5 ✓ Clean C(C(=O)[O-])C(CC(=O)[O-])(C(=O)[O-])O
NCA RCSB PDB B4G043 122.1 Da LogP 0.18 TPSA 56.0 ✓ Ro5 ✓ Clean c1cc(cnc1)C(=O)N
OLC RCSB PDB P00323 356.5 Da LogP 4.92 TPSA 66.8 ✓ Ro5 ✓ Clean CCCCCCCC\C=C/CCCCCCCC(=O)OC[C@@H](CO)O
RBF RCSB PDB P00323 376.4 Da LogP -1.72 TPSA 161.6 ✓ Ro5 ✓ Clean Cc1cc2c(cc1C)N(C3=NC(=O)NC(=O)C3=N2)C[C@@H]([C@…

PDB and ChEMBL records on this protein are shown in full. ChEMBL records from similar proteins are capped at the top 100 per protein (by pchembl) and ZINC at the top 50 (Tanimoto ≥ 0.5). ADME columns are descriptor-based screening flags, not experimental toxicity results.