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.
0  structures 1464  species 0  interactions 1841  sequences 4  architectures

Family: ArsB (PF02040)

Summary: Arsenical pump membrane protein

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

This is the Wikipedia entry entitled "Ars operon". More...

Ars operon Edit Wikipedia article

Anion-transporting ATPase
Identifiers
Symbol ArsA_ATPase
Pfam PF02374
Pfam clan CL0023
SCOP 1f48
SUPERFAMILY 1f48
TCDB 3.A.4
ArsB
Identifiers
Symbol ArsB
Pfam PF02040
Pfam clan CL0182
InterPro IPR000802
TCDB 3.A.4
ArsC
PDB 1rw1 EBI.jpg
yffb (pa3664) protein
Identifiers
Symbol ArsC
Pfam PF03960
Pfam clan CL0172
InterPro IPR006660
SCOP 1i9d
SUPERFAMILY 1i9d
ArsD
Identifiers
Symbol ArsD
Pfam PF06953
Pfam clan CL0172
InterPro IPR010712

In molecular biology, the ars operon is an operon found in several bacterial taxon. It is required for the detoxification of arsenate, arsenite, and antimonite.[1] This system transports arsenite and antimonite out of the cell. The pump is composed of two polypeptides, the products of the arsA and arsB genes. This two-subunit enzyme produces resistance to arsenite and antimonite. Arsenate, however, must first be reduced to arsenite before it is extruded. A third gene, arsC, expands the substrate specificity to allow for arsenate pumping and resistance. ArsC is an approximately 150-residue arsenate reductase that uses reduced glutathione (GSH) to convert arsenate to arsenite with a redox active cysteine residue in the active site. ArsC forms an active quaternary complex with GSH, arsenate, and glutaredoxin 1 (Grx1). The three ligands must be present simultaneously for reduction to occur.[2]

ArsA and ArsB

ArsA and ArsB form an anion-translocating ATPase.[3] The ArsB protein is distinguished by its overall hydrophobic character, in keeping with its role as a membrane-associated channel. Sequence analysis reveals the presence of 13 putative transmembrane (TM) regions.

ArsC

The arsC protein structure has been solved.[4] It belongs to the thioredoxin superfamily fold which is defined by a beta-sheet core surrounded by alpha-helices. The active cysteine residue of ArsC is located in the loop between the first beta-strand and the first helix, which is also conserved in the Spx protein and its homologues.

The arsC family also comprises the Spx proteins which are Gram-positive bacterial transcription factors that regulate the transcription of multiple genes in response to disulphide stress.[5]

ArsD and ArsR

ArsD is a trans-acting repressor of the arsRDABC operon that confers resistance to arsenicals and antimonials in Escherichia coli. It possesses two-pairs of vicinal cysteine residues, Cys(12)-Cys(13) and Cys(112)-Cys(113), that potentially form separate binding sites for the metalloids that trigger dissociation of ArsD from the operon. However, as a homodimer it has four vicinal cysteine pairs.[6] The ArsD family consists of several bacterial arsenical resistance operon trans-acting repressor ArsD proteins.

ArsR is a trans-acting regulatory protein. It acts as a repressor on the arsRDABC operon when no arsenic is present in the cell. When arsenic is present in the cell ArsR will lose affinity for the operator and RNA polymerase can transcribe the arsDCAB genes.[7][8] ArsD and ArsR work together to regulate the ars operon.[9]

References

  1. ^ Carlin A, Shi W, Dey S, Rosen BP (February 1995). "The ars operon of Escherichia coli confers arsenical and antimonial resistance". J. Bacteriol. 177 (4): 981–6. PMC 176692. PMID 7860609. 
  2. ^ Liu J, Rosen BP (August 1997). "Ligand interactions of the ArsC arsenate reductase". J. Biol. Chem. 272 (34): 21084–9. doi:10.1074/jbc.272.34.21084. PMID 9261111. 
  3. ^ Rosen BP (1990). "The plasmid-encoded arsenical resistance pump: an anion-translocating ATPase.". Res Microbiol 141 (3): 336–41. doi:10.1016/0923-2508(90)90008-e. PMID 1704144. 
  4. ^ Martin P, DeMel S, Shi J, Gladysheva T, Gatti DL, Rosen BP, Edwards BF (November 2001). "Insights into the structure, solvation, and mechanism of ArsC arsenate reductase, a novel arsenic detoxification enzyme". Structure 9 (11): 1071–81. doi:10.1016/S0969-2126(01)00672-4. PMID 11709171. 
  5. ^ Zuber P (April 2004). "Spx-RNA polymerase interaction and global transcriptional control during oxidative stress". J. Bacteriol. 186 (7): 1911–8. doi:10.1128/jb.186.7.1911-1918.2004. PMC 374421. PMID 15028674. 
  6. ^ Li S, Rosen BP, Borges-Walmsley MI, Walmsley AR (July 2002). "Evidence for cooperativity between the four binding sites of dimeric ArsD, an As(III)-responsive transcriptional regulator". J. Biol. Chem. 277 (29): 25992–6002. doi:10.1074/jbc.M201619200. PMID 11980902. 
  7. ^ http://www.springerimages.com/Images/RSS/1-10.1007_s00216-009-2785-x-0
  8. ^ http://www.ncbi.nlm.nih.gov/pubmed/9188467?dopt=Abstract
  9. ^ http://www.jbc.org/content/272/22/14257.long

This article incorporates text from the public domain Pfam and InterPro IPR006660

This article incorporates text from the public domain Pfam and InterPro IPR000802

This article incorporates text from the public domain Pfam and InterPro IPR010712

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.

Arsenical pump membrane protein Provide feedback

No Pfam abstract.

Internal database links

External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR000802

Arsenic is a toxic metalloid whose trivalent and pentavalent ions inhibit a variety of biochemical processes. Operons that encode arsenic resistance have been found in multicopy plasmids from both Gram-positive and Gram-negative bacteria [PUBMED:7721697]. The resistance mechanism is encoded from a single operon, which houses an anion pump. The pump has two polypeptide components: a catalytic subunit (the ArsA protein), which functions as an oxyanion-stimulated ATPase; and an arsenite export component (the ArsB protein), which is associated with the inner membrane [PUBMED:1688427]. The ArsA and ArsB proteins are thought to form a membrane complex that functions as an anion-translocating ATPase.

The ArsB protein is distinguished by its overall hydrophobic character, in keeping with its role as a membrane-associated channel. Sequence analysis reveals the presence of 13 putative transmembrane (TM) regions.

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 IT (CL0182), which has the following description:

This superfamily of secondary carriers specific for cationic and anionic compounds, has been termed the ion transporter (IT) superfamily [1].

The clan contains the following 17 members:

ABG_transport ArsB CitMHS DctM DcuA_DcuB DcuC DUF1504 DUF1646 DUF401 GntP_permease Lactate_perm MatC_N Na_H_antiport_2 Na_H_antiporter Na_sulph_symp NhaB SCFA_trans

Alignments

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...

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.

  Seed
(4)
Full
(1841)
Representative proteomes NCBI
(2231)
Meta
(187)
RP15
(93)
RP35
(207)
RP55
(283)
RP75
(343)
Jalview View  View  View  View  View  View  View  View 
HTML View  View  View  View  View  View     
PP/heatmap 1 View  View  View  View  View     
Pfam viewer View  View             

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

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

Format an alignment

  Seed
(4)
Full
(1841)
Representative proteomes NCBI
(2231)
Meta
(187)
RP15
(93)
RP35
(207)
RP55
(283)
RP75
(343)
Alignment:
Format:
Order:
Sequence:
Gaps:
Download/view:

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.

  Seed
(4)
Full
(1841)
Representative proteomes NCBI
(2231)
Meta
(187)
RP15
(93)
RP35
(207)
RP55
(283)
RP75
(343)
Raw Stockholm Download   Download   Download   Download   Download   Download   Download   Download  
Gzipped Download   Download   Download   Download   Download   Download   Download   Download  

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.

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...

Trees

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: IPR000802
Previous IDs: none
Type: Family
Author: Mian N, Bateman A
Number in seed: 4
Number in full: 1841
Average length of the domain: 367.80 aa
Average identity of full alignment: 44 %
Average coverage of the sequence by the domain: 95.11 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 22.2 22.2
Trusted cut-off 22.2 22.2
Noise cut-off 22.1 22.1
Model length: 423
Family (HMM) version: 10
Download: download the raw HMM for this family

Species distribution

Sunburst controls

Show

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

Hide

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

Loading...

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.