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2  structures 10957  species 0  interactions 29284  sequences 7  architectures

Family: Multi_Drug_Res (PF00893)

Summary: Small Multidrug Resistance protein

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This is the Wikipedia entry entitled "Small multidrug resistance protein". More...

Small multidrug resistance protein Edit Wikipedia article

Small Multidrug Resistance protein
Symbol Multi_Drug_Res
Pfam PF00893
InterPro IPR000390
SCOP 1s7b
TCDB 2.A.7
OPM protein 2f2m

Small multidrug resistance protein is a family of integral membrane proteins which confer drug resistance to a wide range of toxic compounds by removing them for the cells. The efflux is coupled to an influx of protons. An example is Escherichia coli mvrC P23895 which prevents the incorporation of methyl viologen into cells[1] and is involved in ethidium bromide efflux.[2]


  1. ^ Morimyo M, Hongo E, Hama-inaba H, Machida I (1992). "Cloning and characterization of the mvrC gene of Escherichia coli K-12 which confers resistance against methyl viologen toxicity". Nucleic Acids Res. 20 (12): 3159–3165. doi:10.1093/nar/20.12.3159. PMC 312453. PMID 1320256. 
  2. ^ Purewal AS (1991). "Nucleotide sequence of the ethidium efflux gene from Escherichia coli". FEMS Microbiol. Lett. 66 (2): 229–231. doi:10.1111/j.1574-6968.1991.tb04870.x. PMID 1936950. 

This article incorporates text from the public domain Pfam and InterPro IPR000390

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.

Small Multidrug Resistance protein Provide feedback

This family is the Small Multidrug Resistance (SMR) family. Several members have been shown to export a range of toxins, including ethidium bromide ([1] and quaternary ammonium compounds [2] through coupling with proton influx [3].

Literature references

  1. Sasatsu M, Shima K, Shibata Y, Kono M; , Nucleic Acids Res 1989;17:10103-10103.: Nucleotide sequence of a gene that encodes resistance to ethidium bromide from a transferable plasmid in Staphylococcus aureus. PUBMED:2602117 EPMC:2602117

  2. Parent R, Roy PH; , J Bacteriol 1992;174:2891-2897.: The chloramphenicol acetyltransferase gene of Tn2424: a new breed of cat. PUBMED:1314803 EPMC:1314803

  3. Yerushalmi H, Lebendiker M, Schuldiner S; , J Biol Chem 1995;270:6856-6863.: EmrE, an Escherichia coli 12-kDa multidrug transporter, exchanges toxic cations and H+ and is soluble in organic solvents. PUBMED:7896833 EPMC:7896833

External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR000390

Members of this family which have been characterised, belong to the small multidrug resistance (Smr) protein family and are integral membrane proteins. They confer resistance to a wide range of toxic compounds by removing them for the cells. The efflux is coupled to an influx of protons. An example is Escherichia coli mvrC SWISSPROT which prevents the incorporation of methyl viologen into cells [PUBMED:1320256] and is involved in ethidium bromide efflux [PUBMED:1936950].

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...

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Pfam Clan

This family is a member of clan DMT (CL0184), which has the following description:

This clan contains a variety of transporters which have 4, 5, 9 or 10 membrane spanning helices. Many of the 10 membrane spanning transporters appear to be a duplication of the 5 spanning unit [1]. Many of these families contain a characteristic glycine rich motif close to the C-terminus.

The clan contains the following 21 members:

CRCB CRT-like CSG2 DMT_6 DMT_YdcZ EamA EmrE Mg_trans_NIPA Multi_Drug_Res Nuc_sug_transp PUNUT RhaT SLC35F Sugar_transport TMEM144 TMEM234 TPT UAA UPF0060 Ureide_permease Zip


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 using the family HMM. We also generate alignments using four representative proteomes (RP) sets, the NCBI sequence database, and our metagenomics sequence database. More...

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

External links

MyHits provides a collection of tools to handle multiple sequence alignments. For example, one can refine a seed alignment (sequence addition or removal, re-alignment or manual edition) and then search databases for remote homologs using HMMER3.

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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.

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Curation and family details

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Seed source: Pfam-B_1082 (release 3.0)
Previous IDs: DUF7; SMR;
Type: Family
Author: Bateman A
Number in seed: 15
Number in full: 29284
Average length of the domain: 93.20 aa
Average identity of full alignment: 34 %
Average coverage of the sequence by the domain: 84.06 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 80369284 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 23.1 23.1
Trusted cut-off 23.1 23.1
Noise cut-off 23.0 23.0
Model length: 93
Family (HMM) version: 15
Download: download the raw HMM for this family

Species distribution

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Archea Archea Eukaryota Eukaryota
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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 Multi_Drug_Res domain has been found. There are 2 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 seqence.

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