ID   XNI_CITK8               Reviewed;         251 AA.
AC   A8AP08;
DT   05-FEB-2008, integrated into UniProtKB/Swiss-Prot.
DT   23-OCT-2007, sequence version 1.
DT   03-AUG-2022, entry version 78.
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=CKO_04156;
OS   Citrobacter koseri (strain ATCC BAA-895 / CDC 4225-83 / SGSC4696).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC   Enterobacteriaceae; Citrobacter.
OX   NCBI_TaxID=290338;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC BAA-895 / CDC 4225-83 / SGSC4696;
RG   The Citrobacter koseri Genome Sequencing Project;
RA   McClelland M., Sanderson E.K., Porwollik S., Spieth J., Clifton W.S.,
RA   Latreille P., Courtney L., Wang C., Pepin K., Bhonagiri V., Nash W.,
RA   Johnson M., Thiruvilangam P., Wilson R.;
RL   Submitted (AUG-2007) to the EMBL/GenBank/DDBJ databases.
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; CP000822; ABV15221.1; -; Genomic_DNA.
DR   RefSeq; WP_012134910.1; NC_009792.1.
DR   AlphaFoldDB; A8AP08; -.
DR   SMR; A8AP08; -.
DR   STRING; 290338.CKO_04156; -.
DR   EnsemblBacteria; ABV15221; ABV15221; CKO_04156.
DR   GeneID; 45137785; -.
DR   KEGG; cko:CKO_04156; -.
DR   HOGENOM; CLU_004675_1_2_6; -.
DR   OMA; WRVDLIP; -.
DR   OrthoDB; 1220182at2; -.
DR   Proteomes; UP000008148; Chromosome.
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; Reference proteome.
FT   CHAIN           1..251
FT                   /note="Flap endonuclease Xni"
FT                   /id="PRO_1000065877"
FT   DOMAIN          160..249
FT                   /note="5'-3' exonuclease"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01192"
FT   REGION          184..189
FT                   /note="Interaction with DNA"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01192"
FT   BINDING         104
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01192"
FT   BINDING         171
FT                   /ligand="K(+)"
FT                   /ligand_id="ChEBI:CHEBI:29103"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01192"
FT   BINDING         172
FT                   /ligand="K(+)"
FT                   /ligand_id="ChEBI:CHEBI:29103"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01192"
FT   BINDING         180
FT                   /ligand="K(+)"
FT                   /ligand_id="ChEBI:CHEBI:29103"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01192"
FT   BINDING         182
FT                   /ligand="K(+)"
FT                   /ligand_id="ChEBI:CHEBI:29103"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01192"
FT   BINDING         185
FT                   /ligand="K(+)"
FT                   /ligand_id="ChEBI:CHEBI:29103"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01192"
SQ   SEQUENCE   251 AA;  28043 MW;  35BADA3F76DD6D47 CRC64;
     MAVHLLIVDA LNLIRRIHAV QGSPCAETCL HALEQLIVHS QPTHAVAVFD DDARNSGWRH
     QRLPDYKAGR PPMPDELHNE MPAIRAAFEQ RGVQCWVSSG NEADDLAATL AVKVTQAGHQ
     ATIVSTDKGY CQLLSPTLRI RDYFQKRWLD APFIEKEFGV LPQQLPDYWG LAGISSSKVP
     GVAGIGPKSA TQLLVQFQTL EGIYAHLDEV AEKWCKKLEA HKEMAFLCRD IARLQTDLHI
     DGNLQQLRLT R