Please note: this site relies heavily on the use of javascript. Without a javascript-enabled browser, this site will not function correctly. Please enable javascript and reload the page, or switch to a different browser.
42  structures 5845  species 0  interactions 129815  sequences 1191  architectures

Family: Sugar_tr (PF00083)

Summary: Sugar (and other) transporter

Pfam includes annotations and additional family information from a range of different sources. These sources can be accessed via the tabs below.

The Pfam group coordinates the annotation of Pfam families in Wikipedia, but we have not yet assigned a Wikipedia article to this family. If you think that a particular Wikipedia article provides good annotation, please let us know.

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.

Sugar (and other) transporter Provide feedback

No Pfam abstract.

Internal database links

External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR005828

This entry represents a subfamily of the major facilitator superfamily. Members in this family include sugar transporters, which are responsible for the binding and transport of various carbohydrates, organic alcohols, and acids in a wide range of prokaryotic and eukaryotic organisms [ PUBMED:3839598 ]. Most but not all members of this family catalyse sugar transport [ PUBMED:26098515 ].

Recent genome-sequencing data and a wealth of biochemical and molecular genetic investigations have revealed the occurrence of dozens of families of primary and secondary transporters. Two such families have been found to occur ubiquitously in all classifications of living organisms. These are the ATP-binding cassette (ABC) superfamily and the major facilitator superfamily (MFS), also called the uniporter-symporter-antiporter family. While ABC family permeases are in general multicomponent primary active transporters, capable of transporting both small molecules and macromolecules in response to ATP hydrolysis the MFS transporters are single-polypeptide secondary carriers capable only of transporting small solutes in response to chemiosmotic ion gradients. Although well over 100 families of transporters have now been recognised and classified, the ABC superfamily and MFS account for nearly half of the solute transporters encoded within the genomes of microorganisms. They are also prevalent in higher organisms. The importance of these two families of transport systems to living organisms can therefore not be overestimated [ PUBMED:9529885 ].

The MFS was originally believed to function primarily in the uptake of sugars but subsequent studies revealed that drug efflux systems, Krebs cycle metabolites, organophosphate:phosphate exchangers, oligosaccharide:H1 symport permeases, and bacterial aromatic acid permeases were all members of the MFS. These observations led to the probability that the MFS is far more widespread in nature and far more diverse in function than had been thought previously. 17 subgroups of the MFS have been identified [ PUBMED:9529885 ].

Evidence suggests that the MFS permeases arose by a tandem intragenic duplication event in the early prokaryotes. This event generated a 2-transmembrane-spanner (TMS) protein topology from a primordial 6-TMS unit. Surprisingly, all currently recognised MFS permeases retain the two six-TMS units within a single polypeptide chain, although in 3 of the 17 MFS families, an additional two TMSs are found [ PUBMED:8987357 ]. Moreover, the well-conserved MFS specific motif between TMS2 and TMS3 and the related but less well conserved motif between TMS8 and TMS9 [ PUBMED:1970645 ] prove to be a characteristic of virtually all of the more than 300 MFS proteins identified.

This family includes sugar and other type of transporters.

Gene Ontology

The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.

Domain organisation

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

Loading domain graphics...

Pfam Clan

This family is a member of clan MFS (CL0015), which has the following description:

The major facilitator superfamily (MFS) is one of the two largest families of membrane transporters found on Earth [1]. It is present ubiquitously in bacteria, archaea, and eukarya and includes members that can function by solute uniport, solute/cation symport, solute/cation antiport and/or solute/solute antiport with inwardly and/or outwardly directed polarity [1]. All permeases of the MFS possess either 12 or 14 transmembrane helices [1].

The clan contains the following 26 members:

Acatn ATG22 BT1 CLN3 DUF5690 Folate_carrier FPN1 LacY_symp MFS_1 MFS_1_like MFS_2 MFS_3 MFS_4 MFS_5 MFS_Mycoplasma Nodulin-like Nuc_H_symport Nucleoside_tran OATP PTR2 PUCC Sugar_tr TLC TRI12 UNC-93 UVB_sens_prot


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...

View options

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.

Representative proteomes UniProt
Jalview View  View  View  View  View  View  View 
HTML View             
PP/heatmap 1            

1Cannot generate PP/Heatmap alignments for seeds; no PP data available

Key: ✓ available, x not generated, not available.

Format an alignment

Representative proteomes UniProt

Download options

We make all of our alignments available in Stockholm format. You can download them here as raw, plain text files or as gzip-compressed files.

Representative proteomes UniProt
Raw Stockholm Download     Download   Download        
Gzipped Download     Download   Download        

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: Prosite hmmls-iteration
Previous IDs: sugar_tr;
Type: Family
Sequence Ontology: SO:0100021
Author: Sonnhammer ELL
Number in seed: 33
Number in full: 129815
Average length of the domain: 360.00 aa
Average identity of full alignment: 17 %
Average coverage of the sequence by the domain: 79.51 %

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 22.3 22.3
Trusted cut-off 22.3 22.3
Noise cut-off 22.2 22.2
Model length: 452
Family (HMM) version: 27
Download: download the raw HMM for this family

Species distribution

Sunburst controls


Weight segments by...

Change the size of the sunburst


Colour assignments

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


Align selected sequences to HMM

Generate a FASTA-format file

Clear selection

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...

Loading sunburst data...

Tree controls


The tree shows the occurrence of this domain across different species. More...


Please note: for large trees this can take some time. While the tree is loading, you can safely switch away from this tab but if you browse away from the family page entirely, the tree will not be loaded.


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 Sugar_tr domain has been found. There are 42 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.

Loading structure mapping...

AlphaFold Structure Predictions

The list of proteins below match this family and have AlphaFold predicted structures. Click on the protein accession to view the predicted structure.

Protein Predicted structure External Information
A0A096PY37 View 3D Structure Click here
A0A0B4KFK6 View 3D Structure Click here
A0A0B4KGW3 View 3D Structure Click here
A0A0B4KHM5 View 3D Structure Click here
A0A0K3AVV4 View 3D Structure Click here
A0A0N7KJ56 View 3D Structure Click here
A0A0N7KMW2 View 3D Structure Click here
A0A0P0V7Z4 View 3D Structure Click here
A0A0P0VDA3 View 3D Structure Click here
A0A0P0VKQ4 View 3D Structure Click here
A0A0P0VRT7 View 3D Structure Click here
A0A0P0VSK4 View 3D Structure Click here
A0A0P0W4Z9 View 3D Structure Click here
A0A0P0WAY2 View 3D Structure Click here
A0A0P0WB92 View 3D Structure Click here
A0A0P0WCA4 View 3D Structure Click here
A0A0P0WFB6 View 3D Structure Click here
A0A0P0WFS2 View 3D Structure Click here
A0A0P0WGH5 View 3D Structure Click here
A0A0P0WGJ2 View 3D Structure Click here
A0A0P0WIF1 View 3D Structure Click here
A0A0P0WM58 View 3D Structure Click here
A0A0P0X7B4 View 3D Structure Click here
A0A0P0X7V4 View 3D Structure Click here
A0A0P0X814 View 3D Structure Click here
A0A0P0XKW0 View 3D Structure Click here
A0A0P0XML3 View 3D Structure Click here
A0A0P0Y4M3 View 3D Structure Click here
A0A0P0Y4S0 View 3D Structure Click here
A0A0R0EAF3 View 3D Structure Click here
A0A0R0ESS5 View 3D Structure Click here
A0A0R0ETB5 View 3D Structure Click here
A0A0R0F0H4 View 3D Structure Click here
A0A0R0F7N4 View 3D Structure Click here
A0A0R0FEL0 View 3D Structure Click here
A0A0R0FHK7 View 3D Structure Click here
A0A0R0FSD4 View 3D Structure Click here
A0A0R0FYN5 View 3D Structure Click here
A0A0R0FZ54 View 3D Structure Click here
A0A0R0FZ59 View 3D Structure Click here