MBEA_ECOLX
ID MBEA_ECOLX Reviewed; 517 AA.
AC P13658;
DT 01-JAN-1990, integrated into UniProtKB/Swiss-Prot.
DT 01-JAN-1990, sequence version 1.
DT 03-AUG-2022, entry version 66.
DE RecName: Full=DNA relaxase MbeA;
DE EC=5.6.2.1;
DE AltName: Full=DNA nickase;
DE AltName: Full=Mobilization protein MbeA;
GN Name=mbeA;
OS Escherichia coli.
OG Plasmid ColE1.
OC Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC Enterobacteriaceae; Escherichia.
OX NCBI_TaxID=562;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=2671664; DOI=10.1007/bf02464922;
RA Boyd A.C., Archer J.A.K., Sherratt D.J.;
RT "Characterization of the ColE1 mobilization region and its protein
RT products.";
RL Mol. Gen. Genet. 217:488-498(1989).
RN [2]
RP FUNCTION AS A RELAXASE, COFACTOR, DETERMINATION OF THE NIC SITE, AND
RP MUTAGENESIS OF TYR-19; HIS-97; GLU-104 AND ASN-106.
RX PubMed=12675806; DOI=10.1046/j.1365-2958.2003.03441.x;
RA Varsaki A., Lucas M., Afendra A.S., Drainas C., de la Cruz F.;
RT "Genetic and biochemical characterization of MbeA, the relaxase involved in
RT plasmid ColE1 conjugative mobilization.";
RL Mol. Microbiol. 48:481-493(2003).
CC -!- FUNCTION: Relaxase involved in plasmid ColE1 conjugative mobilization
CC and is thus essential to promote the specific transfer of the plasmid
CC during conjugation. First catalyzes the specific cleavage of one of the
CC DNA strands at oriT, forming a covalent 5'-phosphotyrosine
CC intermediate. The nic site corresponds to 5'-(1469)CTGG/CTTA(1462)-3'
CC in the cleaved strand. The cleaved strand is then transferred through
CC the dedicated type IV secretion apparatus. MbeA remains covalently
CC linked at the 5' end of the strand, and once in the recipient cell, it
CC probably catalyzes the rejoining of the two ends of the strand, re-
CC forming the circular plasmid DNA. Is functional in vitro without a
CC requirement for the conjugative accessory proteins.
CC {ECO:0000269|PubMed:12675806}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=ATP-independent breakage of single-stranded DNA, followed by
CC passage and rejoining.; EC=5.6.2.1;
CC -!- COFACTOR:
CC Name=Mn(2+); Xref=ChEBI:CHEBI:29035;
CC Evidence={ECO:0000269|PubMed:12675806};
CC Name=Co(2+); Xref=ChEBI:CHEBI:48828;
CC Evidence={ECO:0000269|PubMed:12675806};
CC Name=Ni(2+); Xref=ChEBI:CHEBI:49786;
CC Evidence={ECO:0000269|PubMed:12675806};
CC Note=Divalent metal cation. Can use Mg(2+), Co(2+) or Ni(2+) with
CC similar efficiencies, but is not active in the presence of Mn(2+).
CC {ECO:0000269|PubMed:12675806};
CC -!- SUBUNIT: Interacts with MbeB and MbeC to form the relaxosome.
CC -!- INTERACTION:
CC P13658; P13657: mbeC; NbExp=2; IntAct=EBI-7798346, EBI-7798318;
CC -!- MISCELLANEOUS: The 100 C-terminal amino acids are dispensable for
CC activity.
CC -!- SIMILARITY: To E.coli MbaA and MbkA. {ECO:0000305}.
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DR EMBL; X15873; CAA33883.1; -; Genomic_DNA.
DR PIR; JQ0390; JQ0390.
DR AlphaFoldDB; P13658; -.
DR SMR; P13658; -.
DR IntAct; P13658; 1.
DR MINT; P13658; -.
DR GO; GO:0003677; F:DNA binding; IEA:UniProtKB-KW.
DR GO; GO:0003917; F:DNA topoisomerase type I (single strand cut, ATP-independent) activity; IEA:UniProtKB-EC.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR InterPro; IPR005094; Endonuclease_MobA/VirD2.
DR Pfam; PF03432; Relaxase; 1.
PE 1: Evidence at protein level;
KW Cobalt; Conjugation; DNA-binding; Isomerase; Magnesium; Metal-binding;
KW Mobility protein; Nickel; Plasmid; Topoisomerase.
FT CHAIN 1..517
FT /note="DNA relaxase MbeA"
FT /id="PRO_0000068400"
FT REGION 281..310
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT REGION 380..405
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT REGION 496..517
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT COMPBIAS 294..310
FT /note="Basic and acidic residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT ACT_SITE 19
FT /note="O-(5'-phospho-DNA)-tyrosine intermediate"
FT BINDING 97
FT /ligand="a divalent metal cation"
FT /ligand_id="ChEBI:CHEBI:60240"
FT /evidence="ECO:0000305"
FT BINDING 104
FT /ligand="a divalent metal cation"
FT /ligand_id="ChEBI:CHEBI:60240"
FT /evidence="ECO:0000305"
FT BINDING 106
FT /ligand="a divalent metal cation"
FT /ligand_id="ChEBI:CHEBI:60240"
FT /evidence="ECO:0000305"
FT MUTAGEN 19
FT /note="Y->A: Loss of in vitro DNA-cleavage activity and in
FT vivo functionality."
FT /evidence="ECO:0000269|PubMed:12675806"
FT MUTAGEN 97
FT /note="H->A: Loss of in vitro DNA-cleavage activity and in
FT vivo functionality. No effect on DNA binding around the nic
FT site."
FT /evidence="ECO:0000269|PubMed:12675806"
FT MUTAGEN 104
FT /note="E->A: Loss of in vitro DNA-cleavage activity and in
FT vivo functionality. No effect on DNA binding around the nic
FT site."
FT /evidence="ECO:0000269|PubMed:12675806"
FT MUTAGEN 104
FT /note="E->H: Loss of the in vitro DNA-cleavage and strand-
FT transfer activities but displays 1% of the in vivo wild-
FT type activity; when associated with H-106."
FT /evidence="ECO:0000269|PubMed:12675806"
FT MUTAGEN 106
FT /note="N->A: 4-fold and 3-fold reduction in the in vitro
FT DNA-cleavage and strand-transfer activities, respectively,
FT but no reduction in the in vivo functionality."
FT /evidence="ECO:0000269|PubMed:12675806"
FT MUTAGEN 106
FT /note="N->H: Loss of the in vitro DNA-cleavage and strand-
FT transfer activities but displays 1% of the in vivo wild-
FT type activity; when associated with H-104."
FT /evidence="ECO:0000269|PubMed:12675806"
SQ SEQUENCE 517 AA; 57808 MW; 278E41B2D3B2A08A CRC64;
MIVKFHARGK GGGSGPVDYL LGRERNREGA TVLQGNPEEV RELIDATPFA KKYTSGVLSF
AEKELPPGGR EKVMASFERV LMPGLEKNQY SILWVEHQDK GRLELNFVIP NMELQTGKRL
QPYYDRADRP RIDAWQTLVN HHYGLHDPNA PENRRTLTLP DNLPETKQAL AEGVTRGIDA
LYHAGEIKGR QDVIQALTEA GLEVVRVTRT SISIADPNGG KNIRLKGAFY EQSFADGRGV
REKAERESRI YRENAEQRVQ EARRICKRGC DIKRDENQRR YSPVHSLDRG IAGKTPGRGE
RGDDAAQEGR VKAGREYGHD VTGDSLSPVY REWRDALVSW REDTGEPGRN QEAGRDIAET
EREDMGRGVC AGREQEIPCP SVREISGGDS LSGERVGTSE GVTQSDRAGN TFAERLRAAA
TGLYAAAERM GERLRGIAED VFAYATGQRD AERAGHAVES AGAALERADR TLEPVIQREL
EIREERLIQE REHVLSLERE RQPEIQERTL DGPSLGW
