ID   RUSA_AQUAE              Reviewed;         126 AA.
AC   O67766;
DT   29-AUG-2001, integrated into UniProtKB/Swiss-Prot.
DT   29-AUG-2001, sequence version 2.
DT   03-AUG-2022, entry version 110.
DE   RecName: Full=Crossover junction endodeoxyribonuclease RusA;
DE            EC=3.1.21.10;
DE   AltName: Full=Holliday junction nuclease RusA;
DE   AltName: Full=Holliday junction resolvase;
GN   Name=rusA; OrderedLocusNames=aq_1953;
OS   Aquifex aeolicus (strain VF5).
OC   Bacteria; Aquificae; Aquificales; Aquificaceae; Aquifex.
OX   NCBI_TaxID=224324;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=VF5;
RX   PubMed=9537320; DOI=10.1038/32831;
RA   Deckert G., Warren P.V., Gaasterland T., Young W.G., Lenox A.L.,
RA   Graham D.E., Overbeek R., Snead M.A., Keller M., Aujay M., Huber R.,
RA   Feldman R.A., Short J.M., Olsen G.J., Swanson R.V.;
RT   "The complete genome of the hyperthermophilic bacterium Aquifex aeolicus.";
RL   Nature 392:353-358(1998).
RN   [2]
RP   FUNCTION.
RX   PubMed=11972790; DOI=10.1046/j.1365-2958.2002.02916.x;
RA   Sharples G.J., Bolt E.L., Lloyd R.G.;
RT   "RusA proteins from the extreme thermophile Aquifex aeolicus and
RT   lactococcal phage r1t resolve Holliday junctions.";
RL   Mol. Microbiol. 44:549-559(2002).
CC   -!- FUNCTION: Endonuclease that resolves Holliday junction intermediates
CC       made during homologous genetic recombination and DNA repair. Exhibits
CC       sequence and structure-selective cleavage of four-way DNA junctions,
CC       where it introduces symmetrical nicks in two strands of the same
CC       polarity at the 5' side of CC dinucleotides.
CC       {ECO:0000269|PubMed:11972790}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Endonucleolytic cleavage at a junction such as a reciprocal
CC         single-stranded crossover between two homologous DNA duplexes
CC         (Holliday junction).; EC=3.1.21.10;
CC   -!- COFACTOR:
CC       Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Evidence={ECO:0000250};
CC       Note=Binds 1 Mg(2+) ion per subunit. {ECO:0000250};
CC   -!- SUBUNIT: Homodimer. {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the RusA family. {ECO:0000305}.
CC   -!- SEQUENCE CAUTION:
CC       Sequence=AAC07739.1; Type=Erroneous initiation; Evidence={ECO:0000305};
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DR   EMBL; AE000657; AAC07739.1; ALT_INIT; Genomic_DNA.
DR   PIR; B70467; B70467.
DR   RefSeq; NP_214335.1; NC_000918.1.
DR   AlphaFoldDB; O67766; -.
DR   SMR; O67766; -.
DR   STRING; 224324.aq_1953; -.
DR   EnsemblBacteria; AAC07739; AAC07739; aq_1953.
DR   KEGG; aae:aq_1953; -.
DR   eggNOG; COG4570; Bacteria.
DR   HOGENOM; CLU_139466_1_0_0; -.
DR   InParanoid; O67766; -.
DR   OMA; NWEVRAL; -.
DR   OrthoDB; 1770914at2; -.
DR   Proteomes; UP000000798; Chromosome.
DR   GO; GO:0008821; F:crossover junction endodeoxyribonuclease activity; IEA:UniProtKB-EC.
DR   GO; GO:0000287; F:magnesium ion binding; IEA:InterPro.
DR   GO; GO:0006310; P:DNA recombination; IEA:UniProtKB-KW.
DR   GO; GO:0006281; P:DNA repair; IEA:UniProtKB-KW.
DR   Gene3D; 3.30.1330.70; -; 1.
DR   InterPro; IPR016281; Endonuclease_RusA.
DR   InterPro; IPR008822; Endonuclease_RusA-like.
DR   InterPro; IPR036614; RusA-like_sf.
DR   Pfam; PF05866; RusA; 1.
DR   PIRSF; PIRSF001007; RusA; 1.
DR   SUPFAM; SSF103084; SSF103084; 1.
PE   3: Inferred from homology;
KW   DNA damage; DNA recombination; DNA repair; Endonuclease; Hydrolase;
KW   Magnesium; Metal-binding; Nuclease; Reference proteome.
FT   CHAIN           1..126
FT                   /note="Crossover junction endodeoxyribonuclease RusA"
FT                   /id="PRO_0000192008"
FT   BINDING         76
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000250"
FT   BINDING         78
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000250"
FT   BINDING         97
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   126 AA;  14778 MW;  05BC64FAA7B9F9B1 CRC64;
     MISEMEEIEL YLSKLPVPKS NRYIRPKGGK VFKPPRVTNW EARAIWELRE QFKGDAIDYE
     ISVDITLILP NRRKRDIDNM LKSLWDVMEK AGVIKNDNLI FEVHTVKKIE KGKEGVIIKI
     RPFQSP