P13658 · MBEA_ECOLX

  • Protein
    DNA relaxase MbeA
  • Gene
    mbeA
  • Status
    UniProtKB reviewed (Swiss-Prot)
  • Amino acids
  • Protein existence
    Evidence at protein level
  • Annotation score
    5/5

Function

function

Relaxase involved in plasmid ColE1 conjugative mobilization and is thus essential to promote the specific transfer of the plasmid during conjugation. First catalyzes the specific cleavage of one of the DNA strands at oriT, forming a covalent 5'-phosphotyrosine intermediate. The nic site corresponds to 5'-1469CTGG/CTTA1462-3' in the cleaved strand. The cleaved strand is then transferred through the dedicated type IV secretion apparatus. MbeA remains covalently linked at the 5' end of the strand, and once in the recipient cell, it probably catalyzes the rejoining of the two ends of the strand, re-forming the circular plasmid DNA. Is functional in vitro without a requirement for the conjugative accessory proteins.

Miscellaneous

The 100 C-terminal amino acids are dispensable for activity.

Catalytic activity

  • ATP-independent breakage of single-stranded DNA, followed by passage and rejoining.
    EC:5.6.2.1 (UniProtKB | ENZYME | Rhea)

Cofactor

Mn2+ (UniProtKB | Rhea| CHEBI:29035 )

Co2+ (UniProtKB | Rhea| CHEBI:48828 )

Ni2+ (UniProtKB | Rhea| CHEBI:49786 )

Note: Divalent metal cation. Can use Mg2+, Co2+ or Ni2+ with similar efficiencies, but is not active in the presence of Mn2+.

Features

Showing features for active site, binding site.

Type
IDPosition(s)Description
Active site19O-(5'-phospho-DNA)-tyrosine intermediate
Binding site97a divalent metal cation (UniProtKB | ChEBI)
Binding site104a divalent metal cation (UniProtKB | ChEBI)
Binding site106a divalent metal cation (UniProtKB | ChEBI)

GO annotations

AspectTerm
Molecular FunctionDNA binding
Molecular FunctionDNA topoisomerase type I (single strand cut, ATP-independent) activity
Molecular Functionmetal ion binding

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    DNA relaxase MbeA
  • EC number
  • Alternative names
    • DNA nickase
    • Mobilization protein MbeA

Gene names

    • Name
      mbeA

Encoded on

  • Plasmid ColE1

Organism names

  • Taxonomic identifier
  • Taxonomic lineage
    Bacteria > Pseudomonadota > Gammaproteobacteria > Enterobacterales > Enterobacteriaceae > Escherichia

Accessions

  • Primary accession
    P13658

Phenotypes & Variants

Features

Showing features for mutagenesis.

TypeIDPosition(s)Description
Mutagenesis19Loss of in vitro DNA-cleavage activity and in vivo functionality.
Mutagenesis97Loss of in vitro DNA-cleavage activity and in vivo functionality. No effect on DNA binding around the nic site.
Mutagenesis104Loss of in vitro DNA-cleavage activity and in vivo functionality. No effect on DNA binding around the nic site.
Mutagenesis104Loss of the in vitro DNA-cleavage and strand-transfer activities but displays 1% of the in vivo wild-type activity; when associated with H-106.
Mutagenesis1064-fold and 3-fold reduction in the in vitro DNA-cleavage and strand-transfer activities, respectively, but no reduction in the in vivo functionality.
Mutagenesis106Loss of the in vitro DNA-cleavage and strand-transfer activities but displays 1% of the in vivo wild-type activity; when associated with H-104.

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00000684001-517DNA relaxase MbeA

Interaction

Subunit

Interacts with MbeB and MbeC to form the relaxosome.

Binary interactions

TypeEntry 1Entry 2Number of experimentsIntAct
BINARY P13658mbeC P136572EBI-7798346, EBI-7798318

Protein-protein interaction databases

Structure

Family & Domains

Features

Showing features for region, compositional bias.

Type
IDPosition(s)Description
Region281-310Disordered
Compositional bias294-310Basic and acidic residues
Region380-405Disordered
Region496-517Disordered

Sequence similarities

To E.coli MbaA and MbkA.

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    517
  • Mass (Da)
    57,808
  • Last updated
    1990-01-01 v1
  • Checksum
    278E41B2D3B2A08A
MIVKFHARGKGGGSGPVDYLLGRERNREGATVLQGNPEEVRELIDATPFAKKYTSGVLSFAEKELPPGGREKVMASFERVLMPGLEKNQYSILWVEHQDKGRLELNFVIPNMELQTGKRLQPYYDRADRPRIDAWQTLVNHHYGLHDPNAPENRRTLTLPDNLPETKQALAEGVTRGIDALYHAGEIKGRQDVIQALTEAGLEVVRVTRTSISIADPNGGKNIRLKGAFYEQSFADGRGVREKAERESRIYRENAEQRVQEARRICKRGCDIKRDENQRRYSPVHSLDRGIAGKTPGRGERGDDAAQEGRVKAGREYGHDVTGDSLSPVYREWRDALVSWREDTGEPGRNQEAGRDIAETEREDMGRGVCAGREQEIPCPSVREISGGDSLSGERVGTSEGVTQSDRAGNTFAERLRAAATGLYAAAERMGERLRGIAEDVFAYATGQRDAERAGHAVESAGAALERADRTLEPVIQRELEIREERLIQEREHVLSLERERQPEIQERTLDGPSLGW

Features

Showing features for compositional bias.

TypeIDPosition(s)Description
Compositional bias294-310Basic and acidic residues

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
X15873
EMBL· GenBank· DDBJ
CAA33883.1
EMBL· GenBank· DDBJ
Genomic DNA

Similar Proteins

Disclaimer

Any medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care. Our staff consists of biologists and biochemists that are not trained to give medical advice.
We'd like to inform you that we have updated our Privacy Notice to comply with Europe’s new General Data Protection Regulation (GDPR) that applies since 25 May 2018.
FeedbackHelp