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47  structures 4316  species 0  interactions 5960  sequences 67  architectures

Family: PNTB (PF02233)

Summary: NAD(P) transhydrogenase beta subunit

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This is the Wikipedia entry entitled "NAD(P)+ transhydrogenase (Re/Si-specific)". More...

NAD(P)+ transhydrogenase (Re/Si-specific) Edit Wikipedia article

In enzymology, a NAD(P)+ transhydrogenase (AB-specific) (EC is an enzyme that catalyzes the chemical reaction


Thus, the two substrates of this enzyme are NADPH and NAD+, whereas its two products are NADP+ and NADH.

This enzyme belongs to the family of oxidoreductases, specifically those acting on NADH or NADPH with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is NADPH:NAD+ oxidoreductase (AB-specific). Other names in common use include pyridine nucleotide transhydrogenase, transhydrogenase, NAD(P)+ transhydrogenase, nicotinamide adenine dinucleotide (phosphate) transhydrogenase, NAD+ transhydrogenase, NADH transhydrogenase, nicotinamide nucleotide transhydrogenase, NADPH-NAD+ transhydrogenase, pyridine nucleotide transferase, NADPH-NAD+ oxidoreductase, NADH-NADP+-transhydrogenase, NADPH:NAD+ transhydrogenase, H+-Thase, energy-linked transhydrogenase, and NAD(P)+ transhydrogenase (AB-specific). This enzyme participates in nicotinate and nicotinamide metabolism.

Structural studies

As of late 2007, 19 structures have been solved for this class of enzymes, with PDB accession codes 1NM5, 1PNO, 1PNQ, 1PT9, 1PTJ, 1U28, 1U2D, 1U2G, 1U31, 1X13, 1X14, 1X15, 1XLT, 2BRU, 2FR8, 2FRD, 2FSV, 2OO5, and 2OOR.


Template:Enzyme references

  • Everse, J., Anderson, B. and You, K. (Eds.), The Pyridine Nucleotide Coenzymes, The Pyridine Nucleotide Coenzymes, New York, 1982, p. 279-324.
  • You KS (1985). "Stereospecificity for nicotinamide nucleotides in enzymatic and chemical hydride transfer reactions". CRC. Crit. Rev. Biochem. 17: 313–451. PMID 3157549.

External links

The CAS registry number for this enzyme class is Template:CAS registry.

Template:Enzyme links

Gene Ontology (GO) codes

Template:GO code links

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.

NAD(P) transhydrogenase beta subunit Provide feedback

This family corresponds to the beta subunit of NADP transhydrogenase in prokaryotes, and either the protein N- or C terminal in eukaryotes. The domain is often found in conjunction with PF01262. Pyridine nucleotide transhydrogenase catalyses the reduction of NAD+ to NADPH. A complete loss of activity occurs upon mutation of Gly314 in E. coli [1].

Literature references

  1. Ahmad S, Glavas NA, Bragg PD; , Eur J Biochem 1992;207:733-739.: A mutation at Gly314 of the beta subunit of the Escherichia coli pyridine nucleotide transhydrogenase abolishes activity and affects the NADP(H)-induced conformational change. PUBMED:1633824 EPMC:1633824

Internal database links

External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR034300

NAD(P) transhydrogenase catalyses the transfer of reducing equivalents between NAD(H) and NADP(H), coupled to the translocation of protons across a membrane [ PUBMED:12788487 ]. It is an integral membrane protein found in most organisms except for yeasts, plants and some bacterial species. In bacterial species it is located in the cytoplasmic membrane, while in mitochondria it is located in the inner membrane. Under most physiological conditions this enzyme synthesises NADPH, driven by consumption of the proton electrochemical gradient. The resulting NADPH is subsequently used for biosynthetic reactions or the reduction of glutathione.

Bacterial NADP(H) transhydrogenases consist of two subunits, an alpha subunit with an NAD(H)-binding domain and a beta subunit with an NADP(H)-binding domain [ PUBMED:12974635 ]. This entry corresponds to the beta subunit of NADP transhydrogenase in prokaryotes, and either the protein N- or C-terminal domain in eukaryotes.

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 FAD_DHS (CL0085), which has the following description:

The members of this family adopt a Rossmann fold, similar to CLAN:CL0063. However, the members of this family are distinguished in that the FAD/NAD cofactor is bound in the opposite direction. In this arrangement, the adenosine moiety is found bound at the second half of the fold. In addition, the conserved GxGxxG motif found in classical NADP binding Rossmann folds is absent. Finally, another distinguishing characteristic is the formation of an internal hydrogen bond in the FAD molecule [1].

The clan contains the following 10 members:

CO_dh DS DUF4917 ETF_alpha PNTB PPS_PS SIR2 SIR2_2 TPP_enzyme_M TPP_enzyme_M_2


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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We make a range of alignments for each Pfam-A family. You can see a description of each above. You can view these alignments in various ways but please note that some types of alignment are never generated while others may not be available for all families, most commonly because the alignments are too large to handle.

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You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.

HMM logo

HMM logos is one way of visualising profile HMMs. Logos provide a quick overview of the properties of an HMM in a graphical form. You can see a more detailed description of HMM logos and find out how you can interpret them here. More...


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.

Note: You can also download the data file for the tree.

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_2220 (release 5.2)
Previous IDs: none
Type: Family
Sequence Ontology: SO:0100021
Author: Bateman A , Mian N
Number in seed: 266
Number in full: 5960
Average length of the domain: 431.9 aa
Average identity of full alignment: 49 %
Average coverage of the sequence by the domain: 72.99 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 61295632 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 31.7 31.7
Trusted cut-off 31.8 31.8
Noise cut-off 31.1 31.6
Model length: 460
Family (HMM) version: 19
Download: download the raw HMM for this family

Species distribution

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Colour assignments

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


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This visualisation provides a simple graphical representation of the distribution of this family across species. You can find the original interactive tree in the adjacent tab. More...

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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 PNTB domain has been found. There are 47 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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AlphaFold Structure Predictions