Protein target profile
VK055_4350
cysteine desulfurase, catalytic subunit CsdA
Promising target candidate with multiple supporting evidence streams.
Automated synthesis of the evidence currently loaded. Review the underlying records before prioritizing this protein.
Main supporting evidence
Risks to review
Evidence coverage
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 (%)
- 30.114 Lower values reduce human off-target concern.
- Human E-value
- 2.07e-07
- Gut microbiome similarity
- 2.3% of screened genomes Lower prevalence suggests narrower overlap with the screened gut microbiome.
Essentiality
- Essential (DEG)
- Y
- DEG identity (%)
- 82.294 Higher values support similarity to known essential genes.
- DEG E-value
- 0.0 Smaller values mean stronger essential-gene similarity.
Localization
- Localization
- Cytoplasmic
Structure confidence
- ColabFold pLDDT
- 95.44 0-100 confidence; >70 supports local structural interpretation.
Binding-site evidence
AlphaFold DB / UniProt modelThe 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.
Cross-references
External database identifiers for this protein, its structures, ligands, and metabolic reactions.
Sequence
Pathways
Sequence
Primary amino-acid sequence viewer.
MNAFNPAHFRAQFPALADAGVYLDSAATALKPLAVIDASDQFYRLSAGNVHRSQFAAAQRLTERYEAARDRVAAWLNAPSGKDIVWTRGTTEAINMVAQSYVRPRLQPGDEIIVSEAEHHANLVPWLMVAGQTGARVVKLPLGADRLPDIASLSALITPRSRVLAIGQMSNVTGGCPDLAQAIRLAHAAGMVVMVDGAQGAVHFPADVQALDIDFYAFSGHKLYGPTGIGALYGKSELLAAMSPWLGGGKMIAEVSFDGFTPQPAPYGLEAGTPNVAGVIGLSAALEWLAQSDIGQAENWSRSLASLAEEELAKRPGFRSFRCQQSSLLAFEFEGIHHSDLVTLLAESGIALRAGQHCAQPLLAALGVSGTLRASFAPYNTQDDVAALVHAVDRALEILVD
Functional annotations
Enzyme classification and Gene Ontology terms linked to this protein.
Enzyme Commission (EC)
1Gene Ontology (GO)
5- GO:0016226 The incorporation of iron and exogenous sulfur into a metallo-sulfur cluster.
- GO:0003824 Catalysis of a biochemical reaction at physiological temperatures. In biologically catalyzed reactions, the reactants are known as substrates, and the catalysts are naturally occurring macromolecular substances known as enzymes. Enzymes possess specific binding sites for substrates, and are usually composed wholly or largely of protein, but RNA that has catalytic activity (ribozyme) is often also regarded as enzymatic.
- GO:0006534 OBSOLETE. The chemical reactions and pathways involving cysteine, 2-amino-3-mercaptopropanoic acid.
- GO:0031071 Catalysis of the reaction: L-cysteine + [enzyme]-cysteine = L-alanine + [enzyme]-S-sulfanylcysteine.
- GO:0030170 Binding to pyridoxal 5' phosphate, 3-hydroxy-5-(hydroxymethyl)-2-methyl4-pyridine carboxaldehyde 5' phosphate, the biologically active form of vitamin B6.
Sequence domains and features
Domain and signature matches imported from InterPro and related databases.
Show feature table
| Start | End | DB | Term | Name |
|---|---|---|---|---|
| 7 | 396 | PANTHER | PTHR43586 | CYSTEINE DESULFURASE |
| 5 | 397 | SUPERFAMILY | SSF53383 | PLP-dependent transferases |
| 5 | 397 | InterPro | IPR015424 | Pyridoxal phosphate-dependent transferase |
| 21 | 392 | CDD | cd06453 | SufS_like |
| 21 | 392 | InterPro | IPR010970 | Cysteine desulfurase, SufS |
| 34 | 292 | Gene3D | G3DSA:3.40.640.10 | - |
| 34 | 292 | InterPro | IPR015421 | Pyridoxal phosphate-dependent transferase, major domain |
| 21 | 389 | Gene3D | G3DSA:3.90.1150.10 | Aspartate Aminotransferase, domain 1 |
| 21 | 389 | InterPro | IPR015422 | Pyridoxal phosphate-dependent transferase, small domain |
| 4 | 401 | NCBIfam | TIGR03392 | cysteine desulfurase CsdA |
| 4 | 401 | InterPro | IPR022471 | Cysteine desulphurase, catalytic subunit, CsdA |
| 34 | 292 | FunFam | G3DSA:3.40.640.10:FF:000081 | Cysteine desulfurase CsdA |
| 58 | 78 | Coils | Coil | Coil |
| 213 | 232 | ProSitePatterns | PS00595 | Aminotransferases class-V pyridoxal-phosphate attachment site. |
| 213 | 232 | InterPro | IPR020578 | Aminotransferase class-V, pyridoxal-phosphate binding site |
| 21 | 388 | Pfam | PF00266 | Aminotransferase class-V |
| 21 | 388 | InterPro | IPR000192 | Aminotransferase class V domain |
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.
How colors and pocket overlays are used
Pocket details Inspect a specific pocket, or open the full viewer
- Method
- -
- Score
- -
- Visible layer
- -
- Residues
- -
- Pocket properties
- -
Selecting a pocket opens its details and centers the viewer without clearing other active layers. Use Focus this pocket when you want to hide the rest; use Surface for the wider residue environment.
Binding pockets · FPocket
Druggability: high ≥ 0.7 · medium 0.4–0.69 · low < 0.4
Binding pockets · P2Rank
Probability: high ≥ 0.5 · medium 0.2–0.49 · low < 0.2
Binding pockets · P2Rank
Probability: high ≥ 0.5 · medium 0.2–0.49 · low < 0.2
All structural evidence
Structural evidence
0 + 2Experimental 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_A0A0H3GSG6
|
AlphaFold DB | — | — | full sequence | — | Viewing |
|
ColabFold
VK055_4350
|
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.
Structural ligand evidence is available for this target.
Highest-confidence structural evidence: ligands co-crystallized with this exact protein. If the source PDB is loaded in Target, use Open crystal to inspect it in the structure viewer.
No PDB structure with a co-crystallized ligand found for this exact protein.
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.
| Ligand | Source crystal | UniProt (homolog) | MW · LogP · TPSA | Lipinski | PAINS | SMILES |
|---|---|---|---|---|---|---|
| 7TS RCSB PDB | O32164 | 331.2 Da LogP 0.60 TPSA 157.9 | ✓ Ro5 | ✓ Clean |
Cc1c(c(c(cn1)COP(=O)(O)O)CNC2=CONC2=O)O
|
|
| C6P RCSB PDB | A0A1I5NEH3 | 352.3 Da LogP 0.18 TPSA 149.2 | 1 viol. | ✓ Clean |
Cc1c(c(c(cn1)COP(=O)(O)O)CN[C@@H](CS)C(=O)O)O
|
|
| CKT RCSB PDB | P77444 | 350.3 Da LogP 0.66 TPSA 149.5 | ✓ Ro5 | ✓ Clean |
Cc1c(c(c(cn1)COP(=O)(O)O)C/N=C(\CS)/C(=O)O)O
|
|
| DCS RCSB PDB | O32164 | 333.2 Da LogP -0.78 TPSA 150.2 | ✓ Ro5 | ✓ Clean |
Cc1c(c(c(cn1)COP(=O)(O)O)CN[C@@H]2CONC2=O)O
|
|
| LPG RCSB PDB | P77444 | 99.1 Da LogP -0.97 TPSA 63.3 | ✓ Ro5 | ✓ Clean |
C#CC(C(=O)O)N
|
|
| PDA RCSB PDB | O32164 | 320.2 Da LogP 0.27 TPSA 149.2 | ✓ Ro5 | ✓ Clean |
Cc1c(c(c(cn1)COP(=O)(O)O)CNC(C)C(=O)O)O
|
|
| PMP RCSB PDB | O32164 | 248.2 Da LogP 0.16 TPSA 125.9 | ✓ Ro5 | ✓ Clean |
Cc1c(c(c(cn1)COP(=O)(O)O)CN)O
|
|
| SEC RCSB PDB | P77444 | 168.1 Da LogP -1.28 TPSA 63.3 | ✓ Ro5 | ✓ Clean |
C([C@@H](C(=O)O)N)[SeH]
|
|
| TLA RCSB PDB | Q46925 | 150.1 Da LogP -2.12 TPSA 115.1 | ✓ Ro5 | ✓ Clean |
[C@@H]([C@H](C(=O)O)O)(C(=O)O)O
|
Experimental bioactivity from ChEMBL measured directly on this protein. Score = pchembl (−log Ki/IC₅₀; higher = more potent).
No ChEMBL bioactivity data found for this exact protein.
Bioactivity inferred from similar proteins in ChEMBL. Score = pchembl (−log Ki/IC₅₀; higher = more potent).
No ChEMBL hits found through similar proteins.
Proposed virtual-screening candidates from ZINC. Score = Tanimoto similarity to a known binder (0–1; higher = more similar).
| Ligand | Tanimoto | MW · LogP · TPSA | Lipinski | PAINS | SMILES |
|---|---|---|---|---|---|
| ZINC1532902 ZINC | 0.700 | 206.2 Da LogP -0.86 TPSA 132.1 | ✓ Ro5 | ✓ Clean |
O=C(O)CC[C@@](O)(CC(=O)O)C(=O)O
|
| ZINC2018106 ZINC | 0.700 | 206.2 Da LogP -0.86 TPSA 132.1 | ✓ Ro5 | ✓ Clean |
O=C(O)CC[C@](O)(CC(=O)O)C(=O)O
|
| ZINC12359024 ZINC | 0.692 | 210.1 Da LogP -3.40 TPSA 155.5 | 1 viol. | ✓ Clean |
O=C(O)[C@@H](O)[C@H](O)[C@H](O)[C@@H](O)C(=O)O
|
| ZINC13533920 ZINC | 0.692 | 210.1 Da LogP -3.40 TPSA 155.5 | 1 viol. | ✓ Clean |
O=C(O)[C@@H](O)[C@H](O)[C@@H](O)[C@@H](O)C(=O)O
|
| ZINC1532740 ZINC | 0.692 | 210.1 Da LogP -3.40 TPSA 155.5 | 1 viol. | ✓ Clean |
O=C(O)[C@@H](O)[C@H](O)[C@@H](O)[C@H](O)C(=O)O
|
| ZINC1549593 ZINC | 0.692 | 210.1 Da LogP -3.40 TPSA 155.5 | 1 viol. | ✓ Clean |
O=C(O)[C@H](O)[C@H](O)[C@@H](O)[C@@H](O)C(=O)O
|
| ZINC2013424 ZINC | 0.692 | 210.1 Da LogP -3.40 TPSA 155.5 | 1 viol. | ✓ Clean |
O=C(O)[C@@H](O)[C@@H](O)[C@@H](O)[C@H](O)C(=O)O
|
| ZINC3581021 ZINC | 0.692 | 210.1 Da LogP -3.40 TPSA 155.5 | 1 viol. | ✓ Clean |
O=C(O)[C@H](O)[C@@H](O)[C@@H](O)[C@@H](O)C(=O)O
|
| ZINC3860635 ZINC | 0.692 | 210.1 Da LogP -3.40 TPSA 155.5 | 1 viol. | ✓ Clean |
O=C(O)[C@@H](O)[C@@H](O)[C@H](O)[C@H](O)C(=O)O
|
| ZINC5783661 ZINC | 0.692 | 210.1 Da LogP -3.40 TPSA 155.5 | 1 viol. | ✓ Clean |
O=C(O)[C@@H](O)[C@@H](O)[C@H](O)[C@@H](O)C(=O)O
|
| ZINC6072527 ZINC | 0.692 | 210.1 Da LogP -3.40 TPSA 155.5 | 1 viol. | ✓ Clean |
O=C(O)[C@@H](O)[C@@H](O)[C@@H](O)[C@@H](O)C(=O)O
|
| ZINC3593496 ZINC | 0.652 | 206.2 Da LogP -1.16 TPSA 121.1 | ✓ Ro5 | ✓ Clean |
COC(=O)C[C@@](O)(CC(=O)O)C(=O)O
|
| ZINC3593497 ZINC | 0.652 | 206.2 Da LogP -1.16 TPSA 121.1 | ✓ Ro5 | ✓ Clean |
COC(=O)C[C@](O)(CC(=O)O)C(=O)O
|
| ZINC14686440 ZINC | 0.625 | 436.4 Da LogP -2.64 TPSA 247.9 | 1 viol. | ✓ Clean |
O=C(O)C[C@](O)(CC(=O)NCCCCNC(=O)C[C@@](O)(CC(=O…
|
| ZINC14686442 ZINC | 0.625 | 436.4 Da LogP -2.64 TPSA 247.9 | 1 viol. | ✓ Clean |
O=C(O)C[C@@](O)(CC(=O)NCCCCNC(=O)C[C@](O)(CC(=O…
|
| ZINC14686444 ZINC | 0.625 | 436.4 Da LogP -2.64 TPSA 247.9 | 1 viol. | ✓ Clean |
O=C(O)C[C@@](O)(CC(=O)NCCCCNC(=O)C[C@@](O)(CC(=…
|
| ZINC1532708 ZINC | 0.620 | 248.2 Da LogP 0.16 TPSA 125.9 | ✓ Ro5 | ✓ Clean |
Cc1ncc(COP(=O)(O)O)c(CN)c1O
|
| ZINC1532705 ZINC | 0.600 | 249.2 Da LogP 0.20 TPSA 120.1 | ✓ Ro5 | ✓ Clean |
Cc1ncc(COP(=O)(O)O)c(CO)c1O
|
| ZINC1560405156 ZINC | 0.588 | 208.1 Da LogP -1.79 TPSA 155.5 | 1 viol. | ✓ Clean |
O=C(O)/C(O)=C(\O)[C@H](O)[C@H](O)C(=O)O
|
| ZINC1560405157 ZINC | 0.588 | 208.1 Da LogP -1.79 TPSA 155.5 | 1 viol. | ✓ Clean |
O=C(O)/C(O)=C(/O)[C@H](O)[C@H](O)C(=O)O
|
| ZINC13398039 ZINC | 0.577 | 234.2 Da LogP -0.38 TPSA 121.1 | ✓ Ro5 | ✓ Clean |
CC(C)OC(=O)C[C@](O)(CC(=O)O)C(=O)O
|
| ZINC2528012 ZINC | 0.577 | 234.2 Da LogP -0.38 TPSA 121.1 | ✓ Ro5 | ✓ Clean |
CC(C)OC(=O)C[C@@](O)(CC(=O)O)C(=O)O
|
| ZINC146315135 ZINC | 0.560 | 204.2 Da LogP 0.86 TPSA 94.8 | ✓ Ro5 | ✓ Clean |
CCCCC[C@@](O)(CC(=O)O)C(=O)O
|
| ZINC146315336 ZINC | 0.560 | 204.2 Da LogP 0.86 TPSA 94.8 | ✓ Ro5 | ✓ Clean |
CCCCC[C@](O)(CC(=O)O)C(=O)O
|
| ZINC1850353 ZINC | 0.556 | 206.1 Da LogP -0.86 TPSA 132.1 | ✓ Ro5 | ✓ Clean |
O=C(O)CC(O)(CC(=O)O)CC(=O)O
|
| ZINC1656021 ZINC | 0.540 | 233.2 Da LogP 1.01 TPSA 99.9 | ✓ Ro5 | ✓ Clean |
Cc1ncc(COP(=O)(O)O)c(C)c1O
|
| ZINC13398014 ZINC | 0.522 | 220.2 Da LogP -1.07 TPSA 110.1 | ✓ Ro5 | ✓ Clean |
COC(=O)CC(O)(CC(=O)OC)C(=O)O
|
| ZINC3861629 ZINC | 0.522 | 206.1 Da LogP -1.16 TPSA 121.1 | ✓ Ro5 | ✓ Clean |
COC(=O)C(O)(CC(=O)O)CC(=O)O
|
| ZINC1532514 ZINC | 0.519 | 247.1 Da LogP 0.52 TPSA 117.0 | ✓ Ro5 | ✓ Clean |
Cc1ncc(COP(=O)(O)O)c(C=O)c1O
|
| ZINC100969993 ZINC | 0.500 | 359.5 Da LogP 2.70 TPSA 123.9 | ✓ Ro5 | ✓ Clean |
CCCCCCCCCCCCNC(=O)C[C@](O)(CC(=O)O)C(=O)O
|
| ZINC100969996 ZINC | 0.500 | 359.5 Da LogP 2.70 TPSA 123.9 | ✓ Ro5 | ✓ Clean |
CCCCCCCCCCCCNC(=O)C[C@@](O)(CC(=O)O)C(=O)O
|
| ZINC1529331 ZINC | 0.500 | 206.1 Da LogP -2.21 TPSA 149.2 | ✓ Ro5 | ✓ Clean |
O=C(O)C(=O)[C@H](C(=O)O)[C@@H](O)C(=O)O
|
| ZINC1529332 ZINC | 0.500 | 206.1 Da LogP -2.21 TPSA 149.2 | ✓ Ro5 | ✓ Clean |
O=C(O)C(=O)[C@H](C(=O)O)[C@H](O)C(=O)O
|
| ZINC1529333 ZINC | 0.500 | 206.1 Da LogP -2.21 TPSA 149.2 | ✓ Ro5 | ✓ Clean |
O=C(O)C(=O)[C@@H](C(=O)O)[C@@H](O)C(=O)O
|
| ZINC1529334 ZINC | 0.500 | 206.1 Da LogP -2.21 TPSA 149.2 | ✓ Ro5 | ✓ Clean |
O=C(O)C(=O)[C@@H](C(=O)O)[C@H](O)C(=O)O
|
| ZINC1555366 ZINC | 0.500 | 232.3 Da LogP 0.15 TPSA 126.6 | ✓ Ro5 | ✓ Clean |
N[C@@H](CCCCCC[C@H](N)C(=O)O)C(=O)O
|
| ZINC1555367 ZINC | 0.500 | 232.3 Da LogP 0.15 TPSA 126.6 | ✓ Ro5 | ✓ Clean |
N[C@@H](CCCCCC[C@@H](N)C(=O)O)C(=O)O
|
| ZINC1555369 ZINC | 0.500 | 232.3 Da LogP 0.15 TPSA 126.6 | ✓ Ro5 | ✓ Clean |
N[C@H](CCCCCC[C@@H](N)C(=O)O)C(=O)O
|
| ZINC1711854 ZINC | 0.500 | 248.2 Da LogP -0.13 TPSA 149.2 | ✓ Ro5 | ✓ Clean |
O=C(O)CC(CC(=O)O)(CC(=O)O)CC(=O)O
|
| ZINC1720127 ZINC | 0.500 | 218.3 Da LogP -0.24 TPSA 126.6 | ✓ Ro5 | ✓ Clean |
N[C@@H](CCCCC[C@H](N)C(=O)O)C(=O)O
|
| ZINC1720128 ZINC | 0.500 | 218.3 Da LogP -0.24 TPSA 126.6 | ✓ Ro5 | ✓ Clean |
N[C@@H](CCCCC[C@@H](N)C(=O)O)C(=O)O
|
| ZINC1720130 ZINC | 0.500 | 218.3 Da LogP -0.24 TPSA 126.6 | ✓ Ro5 | ✓ Clean |
N[C@H](CCCCC[C@@H](N)C(=O)O)C(=O)O
|
| ZINC3623257 ZINC | 0.500 | 202.2 Da LogP -0.85 TPSA 126.6 | ✓ Ro5 | ✓ Clean |
N[C@@H](C/C=C/C[C@@H](N)C(=O)O)C(=O)O
|
| ZINC4580672 ZINC | 0.500 | 202.2 Da LogP -0.85 TPSA 126.6 | ✓ Ro5 | ✓ Clean |
N[C@@H](C/C=C/C[C@H](N)C(=O)O)C(=O)O
|
| ZINC4580676 ZINC | 0.500 | 202.2 Da LogP -0.85 TPSA 126.6 | ✓ Ro5 | ✓ Clean |
N[C@H](C/C=C/C[C@@H](N)C(=O)O)C(=O)O
|
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.