Q7LXU0 · HJC_SACS2

Function

function

A structure-specific endonuclease that resolves Holliday junction (HJ) intermediates during genetic recombination; may have some degree of sequence preference in a mobile junction. Cleaves 4-way DNA junctions introducing paired nicks in opposing strands, leaving a 5'-terminal phosphate and a 3'-terminal hydroxyl group that are subsequently ligated to produce recombinant products. Can cleave all 4 strands 3 bases 3' of the junction center. Cleaves both mobile and immobile junctions. Modifies the structure of the 4-way DNA junction, a model Holliday junction structure. The protein forms multiple complexes with 4-way DNA, suggesting more than 1 homodimer can bind to each junction.

Miscellaneous

A second Holliday junction resolving enzyme, Hje, with different substrate specificity exists in this organism.

Catalytic activity

  • Endonucleolytic cleavage at a junction such as a reciprocal single-stranded crossover between two homologous DNA duplexes (Holliday junction).
    EC:3.1.21.10 (UniProtKB | ENZYME | Rhea)

Cofactor

Mg2+ (UniProtKB | Rhea| CHEBI:18420 )

Note: Binds 1 Mg2+ ion per subunit.

Activity regulation

Autoinhibits at very high concentrations, possibly because of extreme junction distortion. Inhibition (and activity at low concentrations of enzyme) is stimulated by dsDNA and Sso7d (PubMed:11709558).
Activity stimulated by PCNA subunit PCNA1 (PubMed:17011573).

Features

Showing features for binding site, active site, site.

TypeIDPosition(s)Description
Binding site12Mg2+ (UniProtKB | ChEBI)
Active site32
Binding site42Mg2+ (UniProtKB | ChEBI)
Binding site55Mg2+ (UniProtKB | ChEBI)
Site57Transition state stabilizer

GO annotations

AspectTerm
Molecular Functioncrossover junction DNA endonuclease activity
Molecular FunctionDNA binding
Molecular Functionmagnesium ion binding
Biological ProcessDNA recombination
Biological ProcessDNA repair

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    Crossover junction endodeoxyribonuclease Hjc
  • EC number
  • Short names
    Hjc
  • Alternative names
    • Holliday junction resolvase Hjc

Gene names

    • Name
      hjc
    • ORF names
      ORF-c21_024
    • Ordered locus names
      SSO0575

Organism names

Accessions

  • Primary accession
    Q7LXU0
  • Secondary accessions
    • Q9UWX8

Proteomes

Phenotypes & Variants

Features

Showing features for mutagenesis.

TypeIDPosition(s)Description
Mutagenesis12No cleavage of 4-way junction DNA. Binds junction DNA normally.
Mutagenesis32No cleavage of fixed 4-way junction DNA. Binds junction DNA normally.
Mutagenesis42No cleavage of 4-way junction DNA. Binds junction DNA normally.
Mutagenesis55No cleavage of 4-way junction DNA. Binds junction DNA normally.
Mutagenesis571000-fold less cleavage of 4-way junction DNA. Binds junction DNA normally.
Mutagenesis137-143No interaction with PCNA1.

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00004291581-143Crossover junction endodeoxyribonuclease Hjc

Proteomic databases

Interaction

Subunit

Homodimer (Probable). Interacts with PCNA subunit PCNA1.

Protein-protein interaction databases

Family & Domains

Sequence similarities

Belongs to the Holliday junction resolvase Hjc family.

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    143
  • Mass (Da)
    16,010
  • Last updated
    2011-05-31 v1
  • Checksum
    22099074AECF1279
MNAKKRKGSAVERNIVSRLRDKGFAVVRAPASGSKRKDPIPDIIALKNGVIILIEMKSRKDIEGKIYVRREQAEGIIEFARKSGGSLFLGVKKPGVLKFIPFEKLRRTETGNYVADSEIEGLDLEDLVRLVEAKISRTLDNFL

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
Y18930
EMBL· GenBank· DDBJ
CAB57725.1
EMBL· GenBank· DDBJ
Genomic DNA
AE006641
EMBL· GenBank· DDBJ
AAK40889.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

Disclaimer

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