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336  structures 7820  species 0  interactions 33022  sequences 214  architectures

Family: Nitroreductase (PF00881)

Summary: Nitroreductase family

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This is the Wikipedia entry entitled "Nitroreductase". More...

Nitroreductase Edit Wikipedia article


Nitroreductases are a family of evolutionarily related proteins involved in the reduction of nitrogen-containing compounds, including those containing the nitro functional group. Members of this family utilise flavin mononucleotide as a cofactor and are often found to be homodimers.[1][2]

Members of this family include oxygen-insensitive NAD(P)H nitroreductase (flavin mononucleotide-dependent nitroreductase) (6,7-dihydropteridine reductase) (EC and NADH dehydrogenase (EC A number of these proteins are described as oxidoreductases. They are primarily found in bacterial lineages though a number of eukaryotic homologs have been identified: C. elegans P34273, D. melanogaster Q8T3Q0, Q9VTE7, mouse Q9DCX8 and human O75989. This protein is not found in photosynthetic eukaryotes. The sequences containing this entry in photosynthetic organisms are possible false positives.

The nitroreductase of Enterobacter cloacae was identified by Bryant and Deluca[3] in a strain isolated from a munitions facility, on the basis of its ability to metabolize TNT (trinitrotoluene). Since then many homologues have been identified and the family is now known to include members in diverse organisms, that catalize diverse reactions. The iodotyrosine deiodenase of mammals is a dehalogenase, the BluB of Sinorhizobium meliloti cannibalizes the bound flavin mononucleotideto furnish a critical intermediate in vitamin B12 biosynthesis.

Crystal structures of the E. cloacae and E. coli enzymes have been published with a variety of substrates and analogues bound.

An example of a potential cold-active enzyme for prodrug therapy was described using a cold-active nitroreductase, Ssap-NtrB[4] (Çelik and Yetis, 2012). Despite Ssap-NtrB derived from a mesophilic bacterium, it showed optimal activity at 20°C against cancer prodrugs. Authors comment that the cold-activity of this novel enzyme will be useful for therapies in combination with crymotherapy, exposing the target tissue to low temperatures in order to trigger the enzyme activity to activate the drug only where is required. Moreover, the enzyme could also be used for bioremediation of compounds of explosive and volatile nature in regions where high activity at low temperatures is needed.


Human proteins containing this domain



  1. ^ Hecht HJ, Erdmann H, Park HJ, Sprinzl M, Schmid RD (December 1995). "Crystal structure of NADH oxidase from Thermus thermophilus". Nat. Struct. Biol. 2 (12): 1109–14. doi:10.1038/nsb1295-1109. PMID 8846223.
  2. ^ de Oliveira IM, Henriques JA, Bonatto D (April 2007). "In silico identification of a new group of specific bacterial and fungal nitroreductases-like proteins". Biochem. Biophys. Res. Commun. 355 (4): 919–25. doi:10.1016/j.bbrc.2007.02.049. PMID 17331467.
  3. ^ Bryant, C.; DeLuca, M. (1991-03-05). "Purification and characterization of an oxygen-insensitive NAD(P)H nitroreductase from Enterobacter cloacae". Journal of Biological Chemistry. 266 (7): 4119–4125. ISSN 0021-9258. PMID 1999405.
  4. ^ Çelik, Ayhan; YetiÅŸ, Gülden (2012-06-01). "An unusually cold active nitroreductase for prodrug activations". Bioorganic & Medicinal Chemistry. 20 (11): 3540–3550. doi:10.1016/j.bmc.2012.04.004. PMID 22546205.
This article incorporates text from the public domain Pfam and InterPro: IPR000415

This page is based on a Wikipedia article. The text is available under the Creative Commons Attribution/Share-Alike License.

This tab holds the annotation information that is stored in the Pfam database. As we move to using Wikipedia as our main source of annotation, the contents of this tab will be gradually replaced by the Wikipedia tab.

Nitroreductase family Provide feedback

The nitroreductase family comprises a group of FMN- or FAD-dependent and NAD(P)H-dependent enzymes able to metabolize nitrosubstituted compounds.

Literature references

  1. Hecht HJ, Erdmann H, Park HJ, Sprinzl M, Schmid RD , Nat Struct Biol 1995;2:1109-1114.: Crystal structure of NADH oxidase from Thermus thermophilus. PUBMED:8846223 EPMC:8846223

  2. de Oliveira IM, Henriques JA, Bonatto D; , Biochem Biophys Res Commun. 2007;355:919-925.: In silico identification of a new group of specific bacterial and fungal nitroreductases-like proteins. PUBMED:17331467 EPMC:17331467

Internal database links

External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR029479

The entry represents a domain found in a group of FMN- or FAD-dependent and NAD(P)H-dependent nitroreductases that are able to metabolise nitrosubstituted compounds [ PUBMED:17331467 , PUBMED:8846223 ].

Domain organisation

Below is a listing of the unique domain organisations or architectures in which this domain is found. More...

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Pfam Clan

This family is a member of clan FMN-dep-NRtase (CL0529), which has the following description:

This superfamily is involved in the reduction of nitrogen containing compounds. Members of this family utilise FMN as a cofactor and are often found to be homodimers. Possible characteristics include Oxygen-insensitive NAD(P)H nitroreductase (FMN-dependent nitroreductase) (Dihydropteridine reductase) and NADH dehydrogenase. A number of the proteins are described as oxidoreductases. They are primarily found in bacterial lineages though a number of eukaryotic homologues have been identified: Caenorhabditis elegans, Drosophila melanogaster, mouse and human. These protein are not found in photosynthetic eukaryotes; sequences containing this entry in photosynthetic organisms are possible false positives.

The clan contains the following 5 members:

Dehalogenase MMACHC MMADHC Nitroreductase TM1586_NiRdase


We store a range of different sequence alignments for families. As well as the seed alignment from which the family is built, we provide the full alignment, generated by searching the sequence database (reference proteomes) using the family HMM. We also generate alignments using four representative proteomes (RP) sets and the UniProtKB sequence database. More...

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This page displays the phylogenetic tree for this family's seed alignment. We use FastTree to calculate neighbour join trees with a local bootstrap based on 100 resamples (shown next to the tree nodes). FastTree calculates approximately-maximum-likelihood phylogenetic trees from our seed alignment.

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Curation and family details

This section shows the detailed information about the Pfam family. You can see the definitions of many of the terms in this section in the glossary and a fuller explanation of the scoring system that we use in the scores section of the help pages.

Curation View help on the curation process

Seed source: Pfam-B_481 (release 3.0)
Previous IDs: none
Type: Domain
Sequence Ontology: SO:0000417
Author: Bateman A
Number in seed: 70
Number in full: 33022
Average length of the domain: 147.50 aa
Average identity of full alignment: 18 %
Average coverage of the sequence by the domain: 65.26 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 57096847 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 23.5 23.5
Trusted cut-off 23.5 23.5
Noise cut-off 23.4 23.4
Model length: 168
Family (HMM) version: 26
Download: download the raw HMM for this family

Species distribution

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Archea Archea Eukaryota Eukaryota
Bacteria Bacteria Other sequences Other sequences
Viruses Viruses Unclassified Unclassified
Viroids Viroids Unclassified sequence Unclassified sequence


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For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the Nitroreductase domain has been found. There are 336 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein sequence.

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