Ligand profile

C21

Ligand co-crystallized with a similar protein (Protein Data Bank).

Bound to: VK055_0128 — fadD

Via homolog PDB 4rmn UniProt Q6NC13 Formula C₅H₄O₂S
Mol. weight 128.15 Da
Permeability High
PAINS Clean

Identifiers

Database identifiers and provenance.

Ligand ID
C21
PDB
4rmn
UniProt (similar protein)
Q6NC13
Target protein
VK055_0128

Structure

2D representation rendered from SMILES.

Physicochemical properties

Computed with RDKit from SMILES.

Molecular weight 128.15 Da
LogP (Crippen) 1.45
H-bond donors 1
H-bond acceptors 2
TPSA 37.30 Ų
Rotatable bonds 1
Aromatic rings 1 / 1
Heavy atoms 8
Fraction sp³ C 0.00
Formula C₅H₄O₂S

Drug-likeness

Descriptor-based ADME screening flags from SMILES. These are not experimental toxicity results.

Permeability proxy High

Estimated from TPSA and LogP only: TPSA ≤ 90 Ų and −1 ≤ LogP ≤ 5 are treated as a favorable small-molecule permeability screen.

  • TPSA ≤ 90 Ų 37.3
  • −1 ≤ LogP ≤ 5 1.45
Lipinski's Rule of Five Pass 0 violations
  • MW ≤ 500 Da 128.2
  • LogP ≤ 5 1.45
  • H-bond donors ≤ 5 1
  • H-bond acceptors ≤ 10 2
Veber's rules Pass
  • Rotatable bonds ≤ 10 1
  • TPSA ≤ 140 Ų 37.3
PAINS Clean

No PAINS structural alerts detected.

Chemical representations

Canonical representations for cheminformatics workflows.

SMILES 
c1cc(sc1)C(=O)O
InChI 
InChI=1S/C5H4O2S/c6-5(7)4-2-1-3-8-4/h1-3H,(H,6,7)
InChIKey 
QERYCTSHXKAMIS-UHFFFAOYSA-N

Provenance

Annotation context from LigQ_2, the internal Target step that collects PDB, ChEMBL, and ZINC ligand evidence.

Method
LigQ nearest_k
Source
PDB
Binding sites
PF00501

External resources

Open this ligand in third-party databases and cheminformatics tools.

Other ligands for this protein

Quick navigation to other ligands bound to VK055_0128.

PDB 9

Ligands co-crystallized with this protein (structural evidence).

Ligand PDB entry

ZINC 50

Virtual screening candidates selected by structural similarity to known actives (Tanimoto ≥ 0.5).

Compound Similarity (Tanimoto)