Skip Header

You are using a version of browser that may not display all the features of this website. Please consider upgrading your browser.
Protein

Antitoxin MqsA

Gene

mqsA

Organism
Escherichia coli (strain K12)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

Antitoxin component of a type II toxin-antitoxin (TA) module. Labile antitoxin that binds to the MqsR mRNA interferase toxin and neutralizes its endoribonuclease activity. Overexpression prevents MqsR-mediated cessation of cell growth and inhibition of cell proliferation. Initially reported to act as a cotranscription factor with MqsA (PubMed:19690171, PubMed:20105222). Following further experiments, the MqsR-MqsA complex does not bind DNA and all reported data are actually due to a small fraction of free MqsA alone binding DNA. Addition of MqsR to a preformed MqsA-promoter DNA complex causes dissociation of the MqsA-DNA complex, probably causing derepression of MqsA-repressed transcripts (PubMed:23172222). MqsA binds to 2 palindromes in the promoter region of the mqsRA operon activating its transcription. Binds to other promoters, inducing mcbR and spy and repressing cspD among others (PubMed:20105222). Binds to and represses the rpoS promoter, the master stress regulator, resulting in decreased cyclic-di-GMP, reduced stress resistance, increased cell motility and decreased biofilm formation; in these experiments 5 TA modules are missing (lacks MazEF, RelEB, ChpB, YoeB-YefM, YafQ-DinJ) (PubMed:21516113). An earlier study showed overexpression alone increases biofilm formation, perhaps by repressing cspD; in these experiments the 5 TA modules are present (PubMed:20105222). Represses the csgD promoter. In the presence of stress, when this protein is degraded, the promoters it represses are derepressed, leading to biofilm formation (Probable). This TA system mediates cell growth during bile acid deoxycholate stress by degrading mRNA for probable deoxycholate-binding protein YgiS; bile acid detergents such as deoxycholate are important for host defense against bacterial growth in the gall bladder and duodenum (PubMed:25534751).1 Publication6 Publications

Cofactori

Zn2+4 PublicationsNote: Binds 1 Zn2+ ion per subunit.4 Publications

Temperature dependencei

The MqsR-MqsA complex is exceptionally thermostable with a Tm of 83.4 degress Celsius versus 48.1 degress Celsius for MqsR and 61.1 degress Celsius for MqsA.1 Publication

Sites

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Metal bindingi3 – 31Zinc; structural4 Publications
Metal bindingi6 – 61Zinc; structural4 Publications
Metal bindingi37 – 371Zinc; structural4 Publications
Metal bindingi40 – 401Zinc; structural4 Publications

Regions

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
DNA bindingi85 – 10420H-T-H motifPROSITE-ProRule annotationAdd
BLAST

GO - Molecular functioni

  • metal ion binding Source: UniProtKB-KW
  • sequence-specific DNA binding Source: EcoCyc

GO - Biological processi

  • regulation of transcription, DNA-templated Source: EcoCyc
  • transcription, DNA-templated Source: UniProtKB-KW
Complete GO annotation...

Keywords - Molecular functioni

Repressor

Keywords - Biological processi

Stress response, Transcription, Transcription regulation

Keywords - Ligandi

DNA-binding, Metal-binding, Zinc

Enzyme and pathway databases

BioCyciEcoCyc:G7571-MONOMER.
ECOL316407:JW2989-MONOMER.
MetaCyc:G7571-MONOMER.

Names & Taxonomyi

Protein namesi
Recommended name:
Antitoxin MqsA1 Publication
Gene namesi
Name:mqsA1 Publication
Synonyms:ygiT
Ordered Locus Names:b3021, JW2989
OrganismiEscherichia coli (strain K12)
Taxonomic identifieri83333 [NCBI]
Taxonomic lineageiBacteriaProteobacteriaGammaproteobacteriaEnterobacterialesEnterobacteriaceaeEscherichia
Proteomesi
  • UP000000318 Componenti: Chromosome
  • UP000000625 Componenti: Chromosome

Organism-specific databases

EcoGeneiEG13022. mqsA.

Pathology & Biotechi

Disruption phenotypei

Essential for growth, it cannot be disrupted (PubMed:16768798). A double mqsR-mqsA deletion leads to increased rpoS mRNA levels, resulting in increased cyclic-di-GMP levels, increasing stress resistance, increased biofilm formation (PubMed:21516113). The double mutant has increased metabolism and respiration in the presence of the bile acid deoxycholate and consequently grows less well. Decreases cell survival in the presence of 20% deoxycholate (PubMed:25534751).3 Publications

Mutagenesis

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Mutagenesisi61 – 611R → A or D: Decreases DNA-binding, decreases thermostability of MqsR-MqsA complex. 1 Publication
Mutagenesisi97 – 1015NAFSR → AAFSA: Abolishes DNA-binding, including binding to the rpoS promoter. 2 Publications
Mutagenesisi97 – 971N → A: 50-fold reduction in DNA-binding. 1 Publication
Mutagenesisi101 – 1011R → A: 10-fold reduction in DNA-binding. 1 Publication

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Chaini1 – 131131Antitoxin MqsAPRO_0000149762Add
BLAST

Post-translational modificationi

Degraded in the presence of oxidative stress, maybe by the Lon and/or ClpX proteases.2 Publications

Proteomic databases

PaxDbiQ46864.
PRIDEiQ46864.

Expressioni

Inductioni

Induced by amino acid starvation, glucose starvation and when translation is blocked. Induction is decreased in the absence of the Lon protease suggesting, by homology to other toxin-antitoxin systems, that Lon may degrade the MqsA antitoxin. Transcription is activated by MqsA (PubMed:20105222). It has been suggested that MqsA represses its own operon (PubMed:19690171). Not more induced in persister cells (PubMed:16768798). A member of the mqsRA operon. This operon induced by ectopic expression of toxins RelE, HicA and YafQ but not by MazF or HicA (PubMed:23432955).1 Publication4 Publications

Interactioni

Subunit structurei

Homodimer. Crystallizes as a heterotetramer with MqsA, MqsR-MqsA(2)-MqsR (PubMed:20041169). Purifies as a probable heterohexamer of 2 MqsR dimers and 1 MqsA dimer (PubMed:19690171). Binds promoter DNA as a dimer (PubMed:21068382). When the 2 dissociate the MsqR mRNA interferase becomes active.4 Publications

Binary interactionsi

WithEntry#Exp.IntActNotes
infAP692222EBI-1120353,EBI-1120746
pldBP070002EBI-1120353,EBI-9134416
rbsRP0ACQ03EBI-1120353,EBI-1119646
rpmAP0A7L82EBI-1120353,EBI-546875
rpoEP0AGB62EBI-1120353,EBI-1129580
ybfEP0AAU72EBI-1120353,EBI-9138393

Protein-protein interaction databases

BioGridi4259247. 153 interactions.
DIPiDIP-12226N.
IntActiQ46864. 54 interactions.
STRINGi511145.b3021.

Structurei

Secondary structure

1
131
Legend: HelixTurnBeta strand
Show more details
Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Turni4 – 63Combined sources
Beta strandi7 – 2216Combined sources
Beta strandi25 – 3713Combined sources
Turni38 – 403Combined sources
Beta strandi43 – 453Combined sources
Helixi47 – 6620Combined sources
Helixi71 – 8010Combined sources
Helixi85 – 928Combined sources
Helixi98 – 1036Combined sources
Helixi111 – 12212Combined sources
Helixi124 – 1263Combined sources
Helixi127 – 1304Combined sources

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
2KZ8NMR-A1-131[»]
3FMYX-ray1.40A62-131[»]
3GA8X-ray1.70A1-76[»]
3GN5X-ray2.15A/B1-131[»]
3HI2X-ray2.00A/C1-76[»]
3O9XX-ray2.10A/B1-131[»]
ProteinModelPortaliQ46864.
SMRiQ46864. Positions 1-131.
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiQ46864.

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Domaini74 – 12754HTH cro/C1-typePROSITE-ProRule annotationAdd
BLAST

Domaini

The Zn-binding N-terminal domain (residues 1-65) binds to the MqsR mRNA interferase toxin and makes contact with the DNA phosphate backbone, while the C-terminus (residues 70-131) binds the promoter in a sequence-specific manner. They are linked by a short flexible domain (PubMed:22789559).3 Publications

Sequence similaritiesi

Contains 1 HTH cro/C1-type DNA-binding domain.PROSITE-ProRule annotation

Phylogenomic databases

eggNOGiENOG4105WJ3. Bacteria.
COG1396. LUCA.
HOGENOMiHOG000151625.
KOiK13655.
OMAiGIWDEES.
OrthoDBiEOG6CK7RV.

Family and domain databases

Gene3Di1.10.260.40. 1 hit.
InterProiIPR001387. Cro/C1-type_HTH.
IPR010982. Lambda_DNA-bd_dom.
IPR022452. MqsA.
IPR032758. MqsA/HigA-2.
IPR022453. Znf_MqsA-type.
[Graphical view]
PfamiPF15731. MqsA_antitoxin. 1 hit.
[Graphical view]
SMARTiSM00530. HTH_XRE. 1 hit.
[Graphical view]
SUPFAMiSSF47413. SSF47413. 1 hit.
TIGRFAMsiTIGR03830. CxxCG_CxxCG_HTH. 1 hit.
TIGR03831. YgiT_finger. 1 hit.
PROSITEiPS50943. HTH_CROC1. 1 hit.
[Graphical view]

Sequencei

Sequence statusi: Complete.

Q46864-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MKCPVCHQGE MVSGIKDIPY TFRGRKTVLK GIHGLYCVHC EESIMNKEES
60 70 80 90 100
DAFMAQVKAF RASVNAETVA PEFIVKVRKK LSLTQKEASE IFGGGVNAFS
110 120 130
RYEKGNAQPH PSTIKLLRVL DKHPELLNEI R
Length:131
Mass (Da):14,703
Last modified:November 1, 1996 - v1
Checksum:iAA26A2793AD84447
GO

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
U28377 Genomic DNA. Translation: AAA69189.1.
U00096 Genomic DNA. Translation: AAC76057.1.
AP009048 Genomic DNA. Translation: BAE77077.1.
PIRiC65089.
RefSeqiNP_417493.1. NC_000913.3.
WP_000650107.1. NZ_LN832404.1.

Genome annotation databases

EnsemblBacteriaiAAC76057; AAC76057; b3021.
BAE77077; BAE77077; BAE77077.
GeneIDi945814.
KEGGiecj:JW2989.
eco:b3021.
PATRICi32121456. VBIEscCol129921_3115.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
U28377 Genomic DNA. Translation: AAA69189.1.
U00096 Genomic DNA. Translation: AAC76057.1.
AP009048 Genomic DNA. Translation: BAE77077.1.
PIRiC65089.
RefSeqiNP_417493.1. NC_000913.3.
WP_000650107.1. NZ_LN832404.1.

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
2KZ8NMR-A1-131[»]
3FMYX-ray1.40A62-131[»]
3GA8X-ray1.70A1-76[»]
3GN5X-ray2.15A/B1-131[»]
3HI2X-ray2.00A/C1-76[»]
3O9XX-ray2.10A/B1-131[»]
ProteinModelPortaliQ46864.
SMRiQ46864. Positions 1-131.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

BioGridi4259247. 153 interactions.
DIPiDIP-12226N.
IntActiQ46864. 54 interactions.
STRINGi511145.b3021.

Proteomic databases

PaxDbiQ46864.
PRIDEiQ46864.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsemblBacteriaiAAC76057; AAC76057; b3021.
BAE77077; BAE77077; BAE77077.
GeneIDi945814.
KEGGiecj:JW2989.
eco:b3021.
PATRICi32121456. VBIEscCol129921_3115.

Organism-specific databases

EchoBASEiEB2840.
EcoGeneiEG13022. mqsA.

Phylogenomic databases

eggNOGiENOG4105WJ3. Bacteria.
COG1396. LUCA.
HOGENOMiHOG000151625.
KOiK13655.
OMAiGIWDEES.
OrthoDBiEOG6CK7RV.

Enzyme and pathway databases

BioCyciEcoCyc:G7571-MONOMER.
ECOL316407:JW2989-MONOMER.
MetaCyc:G7571-MONOMER.

Miscellaneous databases

EvolutionaryTraceiQ46864.
PROiQ46864.

Family and domain databases

Gene3Di1.10.260.40. 1 hit.
InterProiIPR001387. Cro/C1-type_HTH.
IPR010982. Lambda_DNA-bd_dom.
IPR022452. MqsA.
IPR032758. MqsA/HigA-2.
IPR022453. Znf_MqsA-type.
[Graphical view]
PfamiPF15731. MqsA_antitoxin. 1 hit.
[Graphical view]
SMARTiSM00530. HTH_XRE. 1 hit.
[Graphical view]
SUPFAMiSSF47413. SSF47413. 1 hit.
TIGRFAMsiTIGR03830. CxxCG_CxxCG_HTH. 1 hit.
TIGR03831. YgiT_finger. 1 hit.
PROSITEiPS50943. HTH_CROC1. 1 hit.
[Graphical view]
ProtoNetiSearch...

Publicationsi

« Hide 'large scale' publications
  1. Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
    Strain: K12 / MG1655 / ATCC 47076.
  2. "Highly accurate genome sequences of Escherichia coli K-12 strains MG1655 and W3110."
    Hayashi K., Morooka N., Yamamoto Y., Fujita K., Isono K., Choi S., Ohtsubo E., Baba T., Wanner B.L., Mori H., Horiuchi T.
    Mol. Syst. Biol. 2:E1-E5(2006) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
    Strain: K12 / W3110 / ATCC 27325 / DSM 5911.
  3. "Persisters: a distinct physiological state of E. coli."
    Shah D., Zhang Z., Khodursky A., Kaldalu N., Kurg K., Lewis K.
    BMC Microbiol. 6:53-53(2006) [PubMed] [Europe PMC] [Abstract]
    Cited for: IDENTIFICATION AS A TOXIN-ANTITOXIN SYSTEM, INDUCTION, DISRUPTION PHENOTYPE.
    Strain: K12.
  4. "MqsR, a crucial regulator for quorum sensing and biofilm formation, is a GCU-specific mRNA interferase in Escherichia coli."
    Yamaguchi Y., Park J.H., Inouye M.
    J. Biol. Chem. 284:28746-28753(2009) [PubMed] [Europe PMC] [Abstract]
    Cited for: FUNCTION AS AN ANTITOXIN, FUNCTION AS A TRANSCRIPTIONAL REGULATOR, SUBUNIT, DNA-BINDING, OPERON STRUCTURE.
  5. "Escherichia coli toxin/antitoxin pair MqsR/MqsA regulate toxin CspD."
    Kim Y., Wang X., Zhang X.S., Grigoriu S., Page R., Peti W., Wood T.K.
    Environ. Microbiol. 12:1105-1121(2010) [PubMed] [Europe PMC] [Abstract]
    Cited for: FUNCTION AS AN ANTITOXIN, DNA-BINDING, FUNCTION AS A TRANSCRIPTION REGULATOR, INDUCTION, POSSIBLE CLEAVAGE BY CLPPX.
    Strain: K12 / BW25113 and K12 / MG1655 / ATCC 47076.
  6. "Three new RelE-homologous mRNA interferases of Escherichia coli differentially induced by environmental stresses."
    Christensen-Dalsgaard M., Jorgensen M.G., Gerdes K.
    Mol. Microbiol. 75:333-348(2010) [PubMed] [Europe PMC] [Abstract]
    Cited for: FUNCTION AS AN MRNA INTERFERASE ANTITOXIN, INDUCTION, OPERON STRUCTURE.
    Strain: K12 / MG1655 / ATCC 47076.
  7. "Antitoxin MqsA helps mediate the bacterial general stress response."
    Wang X., Kim Y., Hong S.H., Ma Q., Brown B.L., Pu M., Tarone A.M., Benedik M.J., Peti W., Page R., Wood T.K.
    Nat. Chem. Biol. 7:359-366(2011) [PubMed] [Europe PMC] [Abstract]
    Cited for: FUNCTION, DISRUPTION PHENOTYPE, POSSIBLE CLEAVAGE BY LON, DNA-BINDING, MUTAGENESIS OF 97-ASN--ARG-101.
    Strain: K12 / MG1655 / ATCC 47076.
  8. "Transcriptional cross-activation between toxin-antitoxin systems of Escherichia coli."
    Kasari V., Mets T., Tenson T., Kaldalu N.
    BMC Microbiol. 13:45-45(2013) [PubMed] [Europe PMC] [Abstract]
    Cited for: INDUCTION BY OTHER TA MODULES.
    Strain: K12 / BW25113.
  9. "The Escherichia coli toxin MqsR destabilizes the transcriptional repression complex formed between the antitoxin MqsA and the mqsRA operon promoter."
    Brown B.L., Lord D.M., Grigoriu S., Peti W., Page R.
    J. Biol. Chem. 288:1286-1294(2013) [PubMed] [Europe PMC] [Abstract]
    Cited for: FUNCTION, BIOPHYSICOCHEMICAL PROPERTIES, DNA-BINDING, MUTAGENESIS OF ARG-61.
  10. "Antitoxin MqsA represses curli formation through the master biofilm regulator CsgD."
    Soo V.W., Wood T.K.
    Sci. Rep. 3:3186-3186(2013) [PubMed] [Europe PMC] [Abstract]
    Cited for: FUNCTION, DNA-BINDING.
    Strain: K12 / BW25113.
  11. "The MqsR/MqsA toxin/antitoxin system protects Escherichia coli during bile acid stress."
    Kwan B.W., Lord D.M., Peti W., Page R., Benedik M.J., Wood T.K.
    Environ. Microbiol. 17:3168-3181(2015) [PubMed] [Europe PMC] [Abstract]
    Cited for: FUNCTION, DISRUPTION PHENOTYPE.
    Strain: K12 / BW25113.
  12. "Preliminary crystallographic analysis of the Escherichia coli antitoxin MqsA (YgiT/b3021) in complex with mqsRA promoter DNA."
    Brown B.L., Page R.
    Acta Crystallogr. F 66:1060-1063(2010) [PubMed] [Europe PMC] [Abstract]
    Cited for: PRELIMINARY CRYSTALLIZATION, COFACTOR, SUBUNIT.
    Strain: K12.
  13. "Three dimensional structure of the MqsR:MqsA complex: a novel TA pair comprised of a toxin homologous to RelE and an antitoxin with unique properties."
    Brown B.L., Grigoriu S., Kim Y., Arruda J.M., Davenport A., Wood T.K., Peti W., Page R.
    PLoS Pathog. 5:E1000706-E1000706(2009) [PubMed] [Europe PMC] [Abstract]
    Cited for: X-RAY CRYSTALLOGRAPHY (1.4 ANGSTROMS) IN COMPLEX WITH ZINC AND MQSR, SUBUNIT, DNA-BINDING, COFACTOR, DOMAIN.
    Strain: K12.
  14. "Structure of the Escherichia coli antitoxin MqsA (YgiT/b3021) bound to its gene promoter reveals extensive domain rearrangements and the specificity of transcriptional regulation."
    Brown B.L., Wood T.K., Peti W., Page R.
    J. Biol. Chem. 286:2285-2296(2011) [PubMed] [Europe PMC] [Abstract]
    Cited for: X-RAY CRYSTALLOGRAPHY (2.1 ANGSTROMS) IN COMPLEX WITH ZINC AND DNA, COFACTOR, SUBUNIT, DOMAIN, MUTAGENESIS OF ASN-97 AND ARG-101.
    Strain: K12.
  15. "Solution structure and biophysical properties of MqsA, a Zn-containing antitoxin from Escherichia coli."
    Papadopoulos E., Collet J.F., Vukojevic V., Billeter M., Holmgren A., Graslund A., Vlamis-Gardikas A.
    Biochim. Biophys. Acta 1824:1401-1408(2012) [PubMed] [Europe PMC] [Abstract]
    Cited for: STRUCTURE BY NMR, COFACTOR, DOMAIN.

Entry informationi

Entry nameiMQSA_ECOLI
AccessioniPrimary (citable) accession number: Q46864
Secondary accession number(s): Q2M9H9
Entry historyi
Integrated into UniProtKB/Swiss-Prot: July 15, 1999
Last sequence update: November 1, 1996
Last modified: July 6, 2016
This is version 113 of the entry and version 1 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programProkaryotic Protein Annotation Program

Miscellaneousi

Keywords - Technical termi

3D-structure, Complete proteome, Reference proteome

Documents

  1. Escherichia coli
    Escherichia coli (strain K12): entries and cross-references to EcoGene
  2. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  3. SIMILARITY comments
    Index of protein domains and families

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into one UniRef entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.