ID   RUSA_BPR1T              Reviewed;         131 AA.
AC   Q38100;
DT   18-MAR-2008, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1996, sequence version 1.
DT   03-AUG-2022, entry version 77.
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; ORFNames=ORF14;
OS   Lactococcus phage r1t (Bacteriophage r1t).
OC   Viruses; Duplodnaviria; Heunggongvirae; Uroviricota; Caudoviricetes;
OC   Caudovirales; Siphoviridae.
OX   NCBI_TaxID=43685;
OH   NCBI_TaxID=1359; Lactococcus lactis subsp. cremoris (Streptococcus cremoris).
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=8730874; DOI=10.1111/j.1365-2958.1996.tb02477.x;
RA   Nauta A., van Sinderen D., Karsens H., Smit E., Venema G., Kok J.;
RT   "Inducible gene expression mediated by a repressor-operator system isolated
RT   from Lactococcus lactis bacteriophage r1t.";
RL   Mol. Microbiol. 19:1331-1341(1996).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=8730875; DOI=10.1111/j.1365-2958.1996.tb02478.x;
RA   van Sinderen D., Karsens H., Kok J., Terpstra P., Ruiters M.H., Venema G.,
RA   Nauta A.;
RT   "Sequence analysis and molecular characterization of the temperate
RT   lactococcal bacteriophage r1t.";
RL   Mol. Microbiol. 19:1343-1355(1996).
RN   [3]
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       Promotes DNA repair. Exhibits sequence and structure-selective cleavage
CC       of four-way DNA junctions, where it introduces symmetrical nicks in two
CC       strands of the same polarity, though it can also cut branched DNA
CC       structures that lack the symmetry of Holliday junctions.
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}.
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DR   EMBL; U38906; AAB18689.1; -; Genomic_DNA.
DR   RefSeq; NP_695042.1; NC_004302.1.
DR   SMR; Q38100; -.
DR   GeneID; 955502; -.
DR   KEGG; vg:955502; -.
DR   Proteomes; UP000001164; Genome.
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; IPR008822; Endonuclease_RusA-like.
DR   InterPro; IPR036614; RusA-like_sf.
DR   Pfam; PF05866; 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..131
FT                   /note="Crossover junction endodeoxyribonuclease rusA"
FT                   /id="PRO_0000324839"
FT   BINDING         85
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000250"
FT   BINDING         87
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000250"
FT   BINDING         106
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   131 AA;  16001 MW;  9245E387434D12A1 CRC64;
     MKFEFEFELD KMPTTQQQKG IKKVKGKLQF YDRRGTNNYS LKAQLMKNKP KECFEKNVPL
     KLSVTFFYAI KQKKRWWQWK TSRPDLDNLM KNLQDYMTKL RYYSDDSQIV WLEAKKVNDE
     KNRIEIEITE V