KpATCC43816 Protein target profile

tRNA nucleotidyltransferase

Accession: VK055_4012

Gene: cca AIK82559.1 3D evidence: AlphaFold DB model + ColabFold model Metabolism Not in network UniProt A0A0H3GXS6
Length 413
Pocket druggability (P2Rank · AlphaFold DB model) 0.641
Direct ligand evidence 0 54 total records
Functional annotation 0 EC 12 GO
Target summary

Promising target candidate with multiple supporting evidence streams.

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 (%)
31.373 Lower values reduce human off-target concern.
Human E-value
9.2e-09
Gut microbiome similarity
4.1% of screened genomes Lower prevalence suggests narrower overlap with the screened gut microbiome.

Essentiality

Essential (DEG)
Y
DEG identity (%)
86.618 Higher values support similarity to known essential genes.
DEG E-value
0.0 Smaller values mean stronger essential-gene similarity.

Structure confidence

ColabFold pLDDT
93.99 0-100 confidence; >70 supports local structural interpretation.

Binding-site evidence

AlphaFold DB / UniProt model

P2Rank's binding-site probability is the primary druggability signal shown across the app; FPocket's druggability score is shown alongside it for comparison. Both estimate small-molecule pocket quality after applying the curated structure priority — neither is experimental binding evidence. The 3D viewer may show a different loaded structure, so visible pockets can differ.

Druggability (P2Rank) 0.641
Structure A0A0H3GXS6
Pocket Pocket 1
Druggability (FPocket) 0.414
Structure A0A0H3GXS6
Pocket Pocket 3
ColabFold model
P2Rank 0.712 · Pocket 1
FPocket 0.41 · Pocket 26
Core conservation Conserved core gene
Roary core
CoreCruncher core
Gut microbiome 196 / 4744 genomes with a hit
Prevalence 4.1%

Metabolic context

Reactions catalyzed, pathway membership, and centrality in the genome-scale metabolic network.

This protein is not associated with the imported metabolic network for this genome.

Browse the genome's metabolic network

Imported from KpATCC43816.sbml · 2026-07-09

Sequence

Primary amino-acid sequence viewer.

MKSYLVGGAVRDALLGLPVKDRDWVVVGATPQQMLDAGYQQVGRDFPVFLHPQSREEYALARTERKSGAGYTGFTCYAAPDVTLEADLLRRDLTVNALAQDADGAIIDPYGGQNDLRQRLLRHVSPAFSEDPLRVLRVARFAARYAHLGFRIAEETQALMAAMVEAGELAHLTPERVWKETESALTTRNPQVFFQTLRDCQALKVLFPEIDALYGVPAPAKWHPEIDTGLHTLMTVTMAAMLSPDVDVRFATLCHDLGKGLTPKALWPRHHGHGPAGVKLVEQLCARLRVPNDIRDLAKLVAEYHDLIHTLPILQPKTLVKLFDSIDAWRKPQRVQQIALTSEADVRGRTGFEASDYPQGRLLLEAWEVAQSVSTKEVVAAGFKGAEIREELTRRRIAAVAQWKEQRCPQPQG

Functional annotations

Enzyme classification and Gene Ontology terms linked to this protein.

12 GO

Subcellular localization

Localization
Cytoplasmic

Gene Ontology (GO)

12
  • GO:0006396 Any process involved in the conversion of one or more primary RNA transcripts into one or more mature RNA molecules.
  • GO:0005524 Binding to ATP, adenosine 5'-triphosphate, a universally important coenzyme and enzyme regulator.
  • GO:0001680 Post-transcriptional addition of the terminal 3' CCA sequence to a tRNA which does not encode this sequence within the primary transcript. CCA addition proceeds by the sequential addition of CTP, CTP, and then ATP to the 3' end of the tRNA, yielding a diphosphate with each nucleotide addition.
  • GO:0004810 Catalysis of the reaction: a tRNA precursor + ATP + 2 CTP = a tRNA with a 3' CCA end + 3 diphosphate.
  • GO:0003723 Binding to an RNA molecule or a portion thereof.
  • GO:0016779 Catalysis of the transfer of a nucleotidyl group from one compound (donor) to another (acceptor).
  • GO:0160016 Catalysis of the reaction: a tRNA with a 3' CCA end + 2 CTP + ATP = a tRNA with a 3' CCACCA end + 3 diphosphate.
  • GO:0004112 Catalysis of the reaction: a nucleoside cyclic phosphate + H2O = a nucleoside phosphate.
  • GO:0000287 Binding to a magnesium (Mg) ion.
  • GO:0016791 Catalysis of the hydrolysis of a phosphoric monoester, releasing a phosphate.
  • GO:0000049 Binding to a transfer RNA.
  • GO:0042245 Any process that results in the repair of damaged RNA.

Sequence domains and features

Domain and signature matches imported from InterPro and related databases.

27 records
Show feature table
Start End DB Term Name
149 212 Pfam PF12627 Probable RNA and SrmB- binding site of polymerase A
149 212 InterPro IPR032828 tRNA nucleotidyltransferase/poly(A) polymerase, RNA and SrmB- binding domain
231 330 CDD cd00077 HDc
231 330 InterPro IPR003607 HD/PDEase domain
2 119 SUPERFAMILY SSF81301 Nucleotidyltransferase
2 119 InterPro IPR043519 Nucleotidyltransferase superfamily
125 350 FunFam G3DSA:1.10.3090.10:FF:000001 Multifunctional CCA protein
1 408 PIRSF PIRSF000813 CCA_bact
1 408 InterPro IPR012006 tRNA nucleotidyltransferase, proteobacteria
125 407 Gene3D G3DSA:1.10.3090.10 -
1 124 Gene3D G3DSA:3.30.460.10 Beta Polymerase, domain 2
1 124 InterPro IPR043519 Nucleotidyltransferase superfamily
231 328 Pfam PF01966 HD domain
231 328 InterPro IPR006674 HD domain
120 402 SUPERFAMILY SSF81891 Poly A polymerase C-terminal region-like
1 118 CDD cd05398 NT_ClassII-CCAase
1 118 InterPro IPR002646 Poly A polymerase, head domain
228 329 ProSiteProfiles PS51831 HD domain profile.
228 329 InterPro IPR006674 HD domain
1 406 PANTHER PTHR47545 MULTIFUNCTIONAL CCA PROTEIN
1 124 FunFam G3DSA:3.30.460.10:FF:000016 Multifunctional CCA protein
1 407 Hamap MF_01261 Multifunctional CCA protein [cca].
1 407 InterPro IPR012006 tRNA nucleotidyltransferase, proteobacteria
4 122 Pfam PF01743 Poly A polymerase head domain
4 122 InterPro IPR002646 Poly A polymerase, head domain
1 401 Hamap MF_01262 CCA-adding enzyme [cca].
1 401 InterPro IPR012006 tRNA nucleotidyltransferase, proteobacteria

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 · P2Rank

Druggability (P2Rank): high ≥ 0.5 · medium 0.2–0.49 · low < 0.2

Pocket 1 P2Rank #1
0.641
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Surrounding area
Pocket 2 P2Rank #2
0.535
Show in viewer
Surrounding area
Pocket 3 P2Rank #3
0.055
Show in viewer
Surrounding area
Pocket 4 P2Rank #4
0.037
Show in viewer
Surrounding area
Pocket 5 P2Rank #5
0.007
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Surrounding area

Binding pockets · FPocket

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

Pocket 1 FPocket #3
0.414
Show in viewer
Surrounding area
Residue sets
UniProt: Binding site:11-11
UniProt: Binding site:137-137
UniProt: Binding site:140-140
UniProt: Binding site:21-21
UniProt: Binding site:23-23
UniProt: Binding site:8-8
UniProt: Binding site:91-91
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_A0A0H3GXS6
AlphaFold DB full sequence Viewing
ColabFold VK055_4012
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.

54 records
Chemistry signal

Structural ligand evidence is available for this target.

Direct evidence 0 same-protein records
Transferred evidence 4 records from similar proteins
Structural ligands 4 0 loaded crystals
Measured bioactivity 0 direct and transferred ChEMBL records
Proposed compounds 50 similarity-based ZINC candidates
Best available ligand signal
2TM PDB via homolog 481.2 Da · LogP -2.10 · TPSA 261.2 Open detail RCSB PDB
APC PDB via homolog Detail RCSB PDB
FLC PDB via homolog Detail RCSB PDB
POP PDB via homolog Detail RCSB PDB
ZINC104864216 ZINC proposed compound · Tanimoto 0.808 Detail ZINC

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
2TM RCSB PDB A0A1C7DQ98 481.2 Da LogP -2.10 TPSA 261.2 2 viol. ✓ Clean C1=CN(C(=O)N=C1N)[C@H]2[C@@H]([C@@H]([C@H](O2)C…
APC RCSB PDB O66728 505.2 Da LogP -1.52 TPSA 269.9 3 viol. ✓ Clean c1nc(c2c(n1)n(cn2)[C@H]3[C@@H]([C@@H]([C@H](O3)…
FLC RCSB PDB Q96Q11 189.1 Da LogP -5.25 TPSA 140.6 ✓ Ro5 ✓ Clean C(C(=O)[O-])C(CC(=O)[O-])(C(=O)[O-])O
POP RCSB PDB O67911 176.0 Da LogP -2.08 TPSA 129.9 ✓ Ro5 ✓ Clean O[P@@](=O)([O-])O[P@@](=O)(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.

Cross-references

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