ID   XNI_ALISL               Reviewed;         257 AA.
AC   B6EGG3;
DT   14-APR-2009, integrated into UniProtKB/Swiss-Prot.
DT   25-NOV-2008, sequence version 1.
DT   03-AUG-2022, entry version 66.
DE   RecName: Full=Flap endonuclease Xni {ECO:0000255|HAMAP-Rule:MF_01192};
DE            Short=FEN {ECO:0000255|HAMAP-Rule:MF_01192};
DE            EC=3.1.-.- {ECO:0000255|HAMAP-Rule:MF_01192};
GN   Name=xni {ECO:0000255|HAMAP-Rule:MF_01192};
GN   Synonyms=ygdG {ECO:0000255|HAMAP-Rule:MF_01192};
GN   OrderedLocusNames=VSAL_I0694;
OS   Aliivibrio salmonicida (strain LFI1238) (Vibrio salmonicida (strain
OS   LFI1238)).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Vibrionales; Vibrionaceae;
OC   Aliivibrio.
OX   NCBI_TaxID=316275;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=LFI1238;
RX   PubMed=19099551; DOI=10.1186/1471-2164-9-616;
RA   Hjerde E., Lorentzen M.S., Holden M.T., Seeger K., Paulsen S., Bason N.,
RA   Churcher C., Harris D., Norbertczak H., Quail M.A., Sanders S.,
RA   Thurston S., Parkhill J., Willassen N.P., Thomson N.R.;
RT   "The genome sequence of the fish pathogen Aliivibrio salmonicida strain
RT   LFI1238 shows extensive evidence of gene decay.";
RL   BMC Genomics 9:616-616(2008).
CC   -!- FUNCTION: Has flap endonuclease activity. During DNA replication, flap
CC       endonucleases cleave the 5'-overhanging flap structure that is
CC       generated by displacement synthesis when DNA polymerase encounters the
CC       5'-end of a downstream Okazaki fragment. {ECO:0000255|HAMAP-
CC       Rule:MF_01192}.
CC   -!- COFACTOR:
CC       Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC         Evidence={ECO:0000255|HAMAP-Rule:MF_01192};
CC       Note=Binds 2 Mg(2+) per subunit. Only one magnesium ion has a direct
CC       interaction with the protein, the other interactions are indirect.
CC       {ECO:0000255|HAMAP-Rule:MF_01192};
CC   -!- COFACTOR:
CC       Name=K(+); Xref=ChEBI:CHEBI:29103;
CC         Evidence={ECO:0000255|HAMAP-Rule:MF_01192};
CC       Note=Binds 1 K(+) per subunit. The potassium ion strongly increases the
CC       affinity for DNA. {ECO:0000255|HAMAP-Rule:MF_01192};
CC   -!- SIMILARITY: Belongs to the Xni family. {ECO:0000255|HAMAP-
CC       Rule:MF_01192}.
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DR   EMBL; FM178379; CAQ78379.1; -; Genomic_DNA.
DR   RefSeq; WP_012549499.1; NC_011312.1.
DR   AlphaFoldDB; B6EGG3; -.
DR   SMR; B6EGG3; -.
DR   STRING; 316275.VSAL_I0694; -.
DR   EnsemblBacteria; CAQ78379; CAQ78379; VSAL_I0694.
DR   KEGG; vsa:VSAL_I0694; -.
DR   eggNOG; COG0258; Bacteria.
DR   HOGENOM; CLU_004675_1_2_6; -.
DR   OMA; IEMARIC; -.
DR   OrthoDB; 1220182at2; -.
DR   Proteomes; UP000001730; Chromosome 1.
DR   GO; GO:0017108; F:5'-flap endonuclease activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0003677; F:DNA binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0000287; F:magnesium ion binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0030955; F:potassium ion binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0033567; P:DNA replication, Okazaki fragment processing; IEA:UniProtKB-UniRule.
DR   CDD; cd09898; H3TH_53EXO; 1.
DR   HAMAP; MF_01192; Xni; 1.
DR   InterPro; IPR020046; 5-3_exonucl_a-hlix_arch_N.
DR   InterPro; IPR002421; 5-3_exonuclease.
DR   InterPro; IPR036279; 5-3_exonuclease_C_sf.
DR   InterPro; IPR020045; DNA_polI_H3TH.
DR   InterPro; IPR038969; FEN.
DR   InterPro; IPR008918; HhH2.
DR   InterPro; IPR029060; PIN-like_dom_sf.
DR   InterPro; IPR022895; Xni.
DR   PANTHER; PTHR42646; PTHR42646; 1.
DR   Pfam; PF01367; 5_3_exonuc; 1.
DR   Pfam; PF02739; 5_3_exonuc_N; 1.
DR   SMART; SM00475; 53EXOc; 1.
DR   SMART; SM00279; HhH2; 1.
DR   SUPFAM; SSF47807; SSF47807; 1.
DR   SUPFAM; SSF88723; SSF88723; 1.
PE   3: Inferred from homology;
KW   DNA-binding; Endonuclease; Hydrolase; Magnesium; Metal-binding; Nuclease;
KW   Potassium.
FT   CHAIN           1..257
FT                   /note="Flap endonuclease Xni"
FT                   /id="PRO_1000138377"
FT   DOMAIN          165..255
FT                   /note="5'-3' exonuclease"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01192"
FT   REGION          189..194
FT                   /note="Interaction with DNA"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01192"
FT   BINDING         109
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01192"
FT   BINDING         176
FT                   /ligand="K(+)"
FT                   /ligand_id="ChEBI:CHEBI:29103"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01192"
FT   BINDING         177
FT                   /ligand="K(+)"
FT                   /ligand_id="ChEBI:CHEBI:29103"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01192"
FT   BINDING         187
FT                   /ligand="K(+)"
FT                   /ligand_id="ChEBI:CHEBI:29103"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01192"
FT   BINDING         190
FT                   /ligand="K(+)"
FT                   /ligand_id="ChEBI:CHEBI:29103"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01192"
SQ   SEQUENCE   257 AA;  29284 MW;  71A5BD362A5D873D CRC64;
     MAIHLVIIDA LNLIRRVHSA QPNQDDIQAV VTTTGRTINR ILKETEPTHI IAVFDHHLQD
     RGWRAEVLPK YKEDRKPMPE ALQKGMDAIQ ESWWKLGIDS LLSDGDEADD LVATLANKVA
     SRNEQVTIVS TDKGYCQLLS PTLRIRDYFQ HRWLDEPFIE KEFGLKPEQL ADYWGLAGIS
     SSKITGIPGI GPKAALEILT QFPTIEAANE SDELPKKYRK KFDEYYNTAI LCRKVAGLRT
     DIELGFNLQD IRYEKPE