A0A2R3U9L2 · A0A2R3U9L2_9CAUD

Function

function

Catalyzes both the 5'-exonucleolytic and structure-specific endonucleolytic hydrolysis of DNA branched nucleic acid molecules and probably plays a role in viral genome replication. Active on flap (branched duplex DNA containing a free single-stranded 5'-end), 5'overhangs and pseudo-Y structures. The substrates require a free, single-stranded 5' end, with endonucleolytic hydrolysis occurring at the junction of double- and single-stranded DNA. This function may be used for example to trim such branched molecules generated by Okazaki fragments synthesis during replication.

Catalytic activity

  • Exonucleolytic cleavage in the 5'- to 3'-direction to yield nucleoside 5'-phosphates.
    EC:3.1.11.3 (UniProtKB | ENZYME | Rhea)

Cofactor

Mg2+ (UniProtKB | Rhea| CHEBI:18420 )

K+ (UniProtKB | Rhea| CHEBI:29103 )

Note: Binds divalent metal cations, probably Mg2+. In vitro low metal concentrations selectively stimulate the endonuclease reaction. Endonuclease activity is suggested to require only the first cation, whereas exonuclease activity is suggested to require binding of both. High pH favors the exonuclase activity whereas low pH favors the endonuclease activity. Metal ions enhance substrate binding. K+ is bound to the H3TH region.

Features

Showing features for binding site.

TypeIDPosition(s)Description
Binding site83DNA (UniProtKB | ChEBI)
Binding site130Mg2+ 2 (UniProtKB | ChEBI); catalytic
Binding site130Mg2+ 1 (UniProtKB | ChEBI); catalytic
Binding site153Mg2+ 2 (UniProtKB | ChEBI); catalytic
Binding site155Mg2+ 3 (UniProtKB | ChEBI)
Binding site155Mg2+ 2 (UniProtKB | ChEBI); catalytic
Binding site201Mg2+ 3 (UniProtKB | ChEBI)
Binding site209K+ (UniProtKB | ChEBI)
Binding site212K+ (UniProtKB | ChEBI)

GO annotations

AspectTerm
Molecular Function5'-flap endonuclease activity
Molecular FunctionDNA binding
Molecular Functiondouble-stranded DNA 5'-3' DNA exonuclease activity
Molecular Functionmetal ion binding
Biological ProcessDNA replication, Okazaki fragment processing
Biological Processviral DNA genome replication

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    Flap endonuclease
  • EC number
  • Short names
    FEN
  • Alternative names
    • 5'-3' exonuclease
    • Exodeoxyribonuclease
      (EC:3.1.11.3
      ) . EC:3.1.11.3 (UniProtKB | ENZYME | Rhea)

Organism names

  • Taxonomic identifier
  • Taxonomic lineage
    Viruses > Duplodnaviria > Heunggongvirae > Uroviricota > Caudoviricetes > Demerecviridae > Markadamsvirinae > Tequintavirus

Accessions

  • Primary accession
    A0A2R3U9L2

Proteomes

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_50263956171-291Flap endonuclease

Expression

Keywords

Family & Domains

Features

Showing features for domain, region.

TypeIDPosition(s)Description
Domain20-2745'-3' exonuclease
Region82-116Helical arch
Region188-224DNA-binding; H3TH

Domain

Three alpha-helices form a helical arch which forms a hole in the protein and through which the 5' flap of the scissile ssDNA is threaded.

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    291
  • Mass (Da)
    33,453
  • Last updated
    2018-06-20 v1
  • Checksum
    76BEFB66E7FDF7BA
MSKSWGKFIEEEEAEMASRRNLMIVDGTNLGFRFKHNNSKKPFASSYVSTIQSLAKSYSARTTIVLGDKGKSAFRLEHLPEYKGNRDEKYSQRTEEEKALDEQFFEYLKDAFELCETTFPTFTIRGVEADDMAAYIVKLIGHLYDHVWLISTDGDWDTLLTDKVSRFSFTTRREYHLRDMYEHHNVDDVEQFISLKAIMGDLGDNIRGVEGIGAKRGYNIIREFGNVLDIIDQLPLPGKQKYIQNLNASEELLYRNLILVDLPTYCVDAIAAVGQDVLDKFTKDILEIAEQ

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
MH102285
EMBL· GenBank· DDBJ
AVQ09856.1
EMBL· GenBank· DDBJ
Genomic DNA

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Disclaimer

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