KpKP13 Protein target profile

Nitrite reductase [NAD(P)H] large subunit

Accession: KP13_04718

Gene: AHE44017.1 3D evidence: ColabFold model UniProt A0A2V3K3L0
Length 1355
Pocket druggability (P2Rank · ColabFold model) 0.884
Direct ligand evidence 0 54 total records
Functional annotation 1 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 (%)
26.689 Lower values reduce human off-target concern.
Human E-value
1.41e-16
Gut microbiome similarity
1.1% 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.

Structure confidence

ColabFold pLDDT
89.5 0-100 confidence; >70 supports local structural interpretation.

Binding-site evidence

ColabFold / curated 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) 0.884
Structure CB_KP13_04718
Pocket Pocket 1
Druggability (FPocket) 0.948
Structure CB_KP13_04718
Pocket Pocket 90
ColabFold model
P2Rank 0.884 · Pocket 1
FPocket 0.948 · Pocket 90
Core conservation Accessory gene
Roary core
CoreCruncher accessory
Gut microbiome 50 / 4744 genomes with a hit
Prevalence 1.1%

Sequence

Primary amino-acid sequence viewer.

MTRRLVVIGNGMAATRLVQRLVERDPARFAITVVGDEPHPAYNRIQLSPLLAGEKTAAQIPLLPAEWYTRHGVCLRSGEAVDEVDIQQRRLRIAETWLPWDELVFATGSRPFIPPLPGIDRPQVMPFRTLADVERILAIPGPAVVIGGGVLGVEAAAALRRHGGEVTLLHRGSGLMAPLTDAFAADELRQQLEARGIRCVLECRIAAIDADGVRLADGRVFRAARVVLATGVQPDSRLAAQSGVLCQRGIVVDRQMASSLPGISAIGECCEIDGQTWGLVAPCLRQAEVLADRLCGAPGEGFVWQDAGTRLKVTGIELFSAGEQQAGEQDDIYTSWDPIDRHYRRLLLRDGRLRGVLLMGDCTAAAALTARLESDEPATVDWLFDPSSTQPQAAGIMTMTKPVLVLVGHGMVGHHFLEQCVSRNLHQQYRIVVFGEERYPAYDRVHLSEYFAGRSAESLSLAAGDFFIEHGIELRLGEAVATIDRDARLVRDAEGHEIHWDKLVLATGSYPFVPPIPGNDLAGCFVYRTLDDLDRIAAHAAAAKSGVVIGGGLLGLEAANALKQLGLETQVVEFAPNLMAVQLDNGGAAMLREKIVALGVGVHTSKATTAIVREADGLRLNFADGGALRTDMVVFSAGIRPQDALARGCALQVGERGGIHIDGQCRTSDPDVLAIGECALWDNKIYGLVAPGYQMARIAAATLAGEDACFSGADMSTKLKLLGVDVASFGDAQGRTPGCQSYQWTDGPQQIYKKIVVSQDGKALLGGVLVGDASDYATLLQMMLNRMALPPRPESLILPALEGAAPKALGVAALPDSAPICSCHNVSKGDICQAVNNGAGDMSAIKSCTRAATGCGGCSALVKQVMEYQLAEQGVEVKKDVCEHFPWSRQEIYHLVRVNHIHTFEQLISRYGQGHGCDVCKPLVASVLASCWNEYLLKPAHLPLQDTNDRYFANIQKDGSYSVVPRMAAGEVTPDGLIAIGQIAKRYQLYSKVTGGQRIDLFGARLEQLPAIWRELADAGFETGHAYGKSLRTVKSCVGSTWCRYGVQDSTGLAVRLEHRYKGLRAPHKIKMAVSGCTRECAEAQGKDIGVIATDKGWNLYVCGNGGMKPRHADLFASDLDEATLIRSIDRLLMFYIRTADRLQRTSTWMDNLEGGVAYLRQVVLEDSLGIGEELEQEMARIVDSYQCEWQTTLNDPQRLALFRSFVNSDQPDEAVQRRDLRGQPQPLLTETLPEGELPSRPWQAVCDLDAIPAQAGIGARLGERQIALFRFGERVYALDNREPGSTANVLSRGLLGDVGGEPVVISPLYKQRIRLRDGWPCDGSEQAVRAWPVKVENGKVWVGNQQLLARAEAS

Functional annotations

Enzyme classification and Gene Ontology terms linked to this protein.

1 EC 12 GO

Subcellular localization

Localization
CytoplasmicMembrane

Enzyme Commission (EC)

1

Gene Ontology (GO)

12
  • 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:0042128 The nitrogen metabolic process that encompasses the uptake of nitrate from the environment and reduction to ammonia, and results in the incorporation of nitrogen derived from nitrate into cellular substances.
  • GO:0008942 Catalysis of the reaction: NH4+ + 3 NAD(P)+ + 2 H2O = nitrite + 3 NAD(P)H + 5 H+.
  • 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:0051536 Binding to an iron-sulfur cluster, a combination of iron and sulfur atoms.
  • GO:0050661 Binding to nicotinamide-adenine dinucleotide phosphate, a coenzyme involved in many redox and biosynthetic reactions; binding may be to either the oxidized form, NADP+, or the reduced form, NADPH.
  • GO:0020037 Binding to a heme, a compound composed of iron complexed in a porphyrin (tetrapyrrole) ring.
  • GO:0051537 Binding to a 2 iron, 2 sulfur (2Fe-2S) cluster; this cluster consists of two iron atoms, with two inorganic sulfur atoms found between the irons and acting as bridging ligands.
  • GO:0051539 Binding to a 4 iron, 4 sulfur (4Fe-4S) cluster; this cluster consists of four iron atoms, with the inorganic sulfur atoms found between the irons and acting as bridging ligands.
  • GO:0008860 Catalysis of the reaction: 2 reduced [2Fe-2S]-[ferredoxin] + NAD+ + H+ = 2 oxidized [2Fe-2S]-[ferredoxin] + NADH.
  • GO:0046872 Binding to a metal ion.
  • GO:0015980 The chemical reactions and pathways by which a cell derives energy from organic compounds; results in the oxidation of the compounds from which energy is released.

Sequence domains and features

Domain and signature matches imported from InterPro and related databases.

73 records
Show feature table
Start End DB Term Name
2 183 SUPERFAMILY SSF51905 FAD/NAD(P)-binding domain
2 183 InterPro IPR036188 FAD/NAD(P)-binding domain superfamily
1027 1191 Gene3D G3DSA:3.30.413.10 Sulfite Reductase Hemoprotein, domain 1
1027 1191 InterPro IPR045854 Nitrite and sulphite reductase 4Fe-4S domain-like superfamily
6 296 Gene3D G3DSA:3.50.50.60 -
6 296 InterPro IPR036188 FAD/NAD(P)-binding domain superfamily
820 867 Pfam PF04324 BFD-like [2Fe-2S] binding domain
820 867 InterPro IPR007419 BFD-like [2Fe-2S]-binding domain
508 642 Gene3D G3DSA:3.50.50.60 -
508 642 InterPro IPR036188 FAD/NAD(P)-binding domain superfamily
1243 1343 ProSiteProfiles PS51296 Rieske [2Fe-2S] iron-sulfur domain profile.
1243 1343 InterPro IPR017941 Rieske [2Fe-2S] iron-sulphur domain
1239 1347 Gene3D G3DSA:2.102.10.10 -
1239 1347 InterPro IPR036922 Rieske [2Fe-2S] iron-sulphur domain superfamily
1075 1093 PRINTS PR00397 Sirohaem Fe-binding site signature
1075 1093 InterPro IPR006066 Nitrite/sulphite reductase iron-sulphur/sirohaem-binding site
1032 1050 PRINTS PR00397 Sirohaem Fe-binding site signature
1032 1050 InterPro IPR006066 Nitrite/sulphite reductase iron-sulphur/sirohaem-binding site
956 1018 Pfam PF03460 Nitrite/Sulfite reductase ferredoxin-like half domain
956 1018 InterPro IPR005117 Nitrite/Sulfite reductase ferredoxin-like domain
308 382 Gene3D G3DSA:3.30.390.30 -
308 382 InterPro IPR016156 FAD/NAD-linked reductase, dimerisation domain superfamily
716 794 Gene3D G3DSA:3.30.390.30 -
716 794 InterPro IPR016156 FAD/NAD-linked reductase, dimerisation domain superfamily
113 230 Gene3D G3DSA:3.50.50.60 -
113 230 InterPro IPR036188 FAD/NAD(P)-binding domain superfamily
1240 1345 ProSiteProfiles PS51300 NADH-nitrite reductase subunit D family profile.
3 372 PANTHER PTHR43809 NITRITE REDUCTASE (NADH) LARGE SUBUNIT
547 706 SUPERFAMILY SSF51905 FAD/NAD(P)-binding domain
547 706 InterPro IPR036188 FAD/NAD(P)-binding domain superfamily
1075 1091 ProSitePatterns PS00365 Nitrite and sulfite reductases iron-sulfur/siroheme-binding site.
1075 1091 InterPro IPR006066 Nitrite/sulphite reductase iron-sulphur/sirohaem-binding site
4 273 Pfam PF07992 Pyridine nucleotide-disulphide oxidoreductase
4 273 InterPro IPR023753 FAD/NAD(P)-binding domain
716 797 FunFam G3DSA:3.30.390.30:FF:000006 Nitrite reductase large subunit
404 685 Pfam PF07992 Pyridine nucleotide-disulphide oxidoreductase
404 685 InterPro IPR023753 FAD/NAD(P)-binding domain
404 1197 NCBIfam TIGR02374 nitrite reductase large subunit NirB
404 1197 InterPro IPR012744 Nitrite reductase [NAD(P)H] large subunit, NirB
405 679 Gene3D G3DSA:3.50.50.60 -
405 679 InterPro IPR036188 FAD/NAD(P)-binding domain superfamily
879 928 CDD cd19944 NirB_Fer2_BFD-like_2
309 374 Pfam PF18267 Rubredoxin NAD+ reductase C-terminal domain
309 374 InterPro IPR041575 NADH-rubredoxin oxidoreductase, C-terminal
716 785 Pfam PF18267 Rubredoxin NAD+ reductase C-terminal domain
716 785 InterPro IPR041575 NADH-rubredoxin oxidoreductase, C-terminal
1029 1201 SUPERFAMILY SSF56014 Nitrite and sulphite reductase 4Fe-4S domain-like
1029 1201 InterPro IPR045854 Nitrite and sulphite reductase 4Fe-4S domain-like superfamily
508 642 FunFam G3DSA:3.50.50.60:FF:000033 Nitrite reductase [NAD(P)H], large subunit
1243 1343 Pfam PF13806 Rieske-like [2Fe-2S] domain
1243 1343 InterPro IPR012748 Rieske-like [2Fe-2S] domain, NirD-type
399 588 SUPERFAMILY SSF51905 FAD/NAD(P)-binding domain
399 588 InterPro IPR036188 FAD/NAD(P)-binding domain superfamily
898 1037 SUPERFAMILY SSF55124 Nitrite/Sulfite reductase N-terminal domain-like
898 1037 InterPro IPR036136 Nitrite/Sulfite reductase ferredoxin-like domain superfamily
1028 1166 Pfam PF01077 Nitrite and sulphite reductase 4Fe-4S domain
1028 1166 InterPro IPR006067 Nitrite/sulphite reductase 4Fe-4S domain
1243 1344 NCBIfam TIGR02378 nitrite reductase small subunit NirD
1243 1344 InterPro IPR012748 Rieske-like [2Fe-2S] domain, NirD-type
1243 1344 CDD cd03529 Rieske_NirD
1242 1345 SUPERFAMILY SSF50022 ISP domain
1242 1345 InterPro IPR036922 Rieske [2Fe-2S] iron-sulphur domain superfamily
143 297 SUPERFAMILY SSF51905 FAD/NAD(P)-binding domain
143 297 InterPro IPR036188 FAD/NAD(P)-binding domain superfamily
819 872 Gene3D G3DSA:1.10.10.1100 -
819 872 InterPro IPR041854 BFD-like [2Fe-2S]-binding domain superfamily
819 871 FunFam G3DSA:1.10.10.1100:FF:000002 Nitrite reductase large subunit
223 239 PRINTS PR00368 FAD-dependent pyridine nucleotide reductase signature
5 24 PRINTS PR00368 FAD-dependent pyridine nucleotide reductase signature
142 160 PRINTS PR00368 FAD-dependent pyridine nucleotide reductase signature
248 270 PRINTS PR00368 FAD-dependent pyridine nucleotide reductase signature
100 118 PRINTS PR00368 FAD-dependent pyridine nucleotide reductase signature
1034 1157 FunFam G3DSA:3.30.413.10:FF:000007 Nitrite reductase [NAD(P)H] large subunit

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.

Loading 3D structure...

Drag to rotate — click the view, then scroll to zoom.

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
0.884
Show in viewer
Surrounding area
Pocket 2 P2Rank #2
0.845
Show in viewer
Surrounding area
Pocket 3 P2Rank #3
0.715
Show in viewer
Surrounding area
Pocket 4 P2Rank #4
0.65
Show in viewer
Surrounding area
Pocket 5 P2Rank #5
0.563
Likely same site as FPocket 90 5.1 Å 22 shared residues 92% of smaller site
Show in viewer
Surrounding area

Binding pockets · FPocket

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

Pocket 1 FPocket #90
0.948 Unusual size
Likely same site as P2Rank 5 5.1 Å 22 shared residues 92% of smaller site
Show in viewer
Surrounding area
Pocket 2 FPocket #1
0.297 Unusual size
Show in viewer
Surrounding area
Pocket 3 FPocket #75
0.205
Show in viewer
Surrounding area
All structural evidence 0 experimental · 1 predicted

Structural evidence

0 + 1

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
ColabFold KP13_04718
ColabFold full sequence Viewing

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
APR PDB via homolog 559.3 Da · LogP -3.28 · TPSA 291.5 Open detail RCSB PDB
AZI PDB via homolog Detail RCSB PDB
BU3 PDB via homolog Detail RCSB PDB
OXY PDB via homolog Detail RCSB PDB
ZINC12360002 ZINC proposed compound · Tanimoto 0.855 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
APR RCSB PDB Q52437 559.3 Da LogP -3.28 TPSA 291.5 3 viol. ✓ Clean c1nc(c2c(n1)n(cn2)[C@H]3[C@@H]([C@@H]([C@H](O3)…
AZI RCSB PDB Q5XC60 42.0 Da LogP 0.87 TPSA 58.7 ✓ Ro5 Alert [N-]=[N+]=[N-]
BU3 RCSB PDB Q47QF8 90.1 Da LogP -0.25 TPSA 40.5 ✓ Ro5 ✓ Clean C[C@H]([C@@H](C)O)O
OXY RCSB PDB Q03Q85 32.0 Da LogP 0.07 TPSA 34.1 ✓ Ro5 ✓ Clean 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.