P13658 (MBEA_ECOLX) Reviewed, UniProtKB/Swiss-Prot
Last modified June 11, 2014. Version 48. History...
Names and origin
|Protein names||Recommended name:|
DNA relaxase MbeA
Mobilization protein MbeA
|Encoded on||Plasmid ColE1|
|Taxonomic identifier||562 [NCBI]|
|Taxonomic lineage||Bacteria › Proteobacteria › Gammaproteobacteria › Enterobacteriales › Enterobacteriaceae › Escherichia|
|Sequence length||517 AA.|
|Protein existence||Evidence at protein level|
General annotation (Comments)
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'-(1469)CTGG/CTTA(1462)-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. Ref.2
ATP-independent breakage of single-stranded DNA, followed by passage and rejoining.
Divalent metal cation. Can use Mg2+, Co2+ and Ni2+ with similar efficiencies, but is not active in the presence of Mn2+. Ref.2
Interacts with MbeB and MbeC to form the relaxosome.
The 100 C-terminal amino acids are dispensable for activity.
To E.coli MbaA and MbkA.
|Gene Ontology (GO)|
Inferred from electronic annotation. Source: UniProtKB-KW
Inferred from electronic annotation. Source: UniProtKB-KWDNA topoisomerase type I activity
Inferred from electronic annotation. Source: UniProtKB-ECmetal ion binding
Inferred from electronic annotation. Source: UniProtKB-KWprotein binding
|Complete GO annotation...|
Sequence annotation (Features)
|Feature key||Position(s)||Length||Description||Graphical view||Feature identifier|
|Chain||1 – 517||517||DNA relaxase MbeA||PRO_0000068400|
|Active site||19||1||O-(5'-phospho-DNA)-tyrosine intermediate|
|Metal binding||97||1||Divalent metal cation Probable|
|Metal binding||104||1||Divalent metal cation Probable|
|Metal binding||106||1||Divalent metal cation Probable|
|Mutagenesis||19||1||Y → A: Loss of in vitro DNA-cleavage activity and in vivo functionality. Ref.2|
|Mutagenesis||97||1||H → A: Loss of in vitro DNA-cleavage activity and in vivo functionality. No effect on DNA binding around the nic site. Ref.2|
|Mutagenesis||104||1||E → A: Loss of in vitro DNA-cleavage activity and in vivo functionality. No effect on DNA binding around the nic site. Ref.2|
|Mutagenesis||104||1||E → H: Loss 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. Ref.2|
|Mutagenesis||106||1||N → A: 4-fold and 3-fold reduction in the in vitro DNA-cleavage and strand-transfer activities, respectively, but no reduction in the in vivo functionality. Ref.2|
|Mutagenesis||106||1||N → H: Loss 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. Ref.2|
|||"Characterization of the ColE1 mobilization region and its protein products."|
Boyd A.C., Archer J.A.K., Sherratt D.J.
Mol. Gen. Genet. 217:488-498(1989) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
|||"Genetic and biochemical characterization of MbeA, the relaxase involved in plasmid ColE1 conjugative mobilization."|
Varsaki A., Lucas M., Afendra A.S., Drainas C., de la Cruz F.
Mol. Microbiol. 48:481-493(2003) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION AS A RELAXASE, COFACTOR, DETERMINATION OF THE NIC SITE, MUTAGENESIS OF TYR-19; HIS-97; GLU-104 AND ASN-106.
|X15873 Genomic DNA. Translation: CAA33883.1.|
3D structure databases
Protein-protein interaction databases
|IntAct||P13658. 1 interaction.|
Protocols and materials databases
Family and domain databases
|InterPro||IPR005094. Endonuclease_MobA/VirD2. |
|Pfam||PF03432. Relaxase. 1 hit. |
|Accession||Primary (citable) accession number: P13658|
|Entry status||Reviewed (UniProtKB/Swiss-Prot)|
|Annotation program||Prokaryotic Protein Annotation Program|