ID   RIFK_NATPD              Reviewed;         232 AA.
AC   Q3IUQ3;
DT   26-FEB-2008, integrated into UniProtKB/Swiss-Prot.
DT   08-NOV-2005, sequence version 1.
DT   03-AUG-2022, entry version 96.
DE   RecName: Full=Riboflavin kinase;
DE            Short=RFK;
DE            EC=2.7.1.161;
DE   AltName: Full=CTP-dependent riboflavin kinase;
DE   AltName: Full=CTP:riboflavin 5'-phosphotransferase;
DE   AltName: Full=Flavokinase;
GN   Name=ribK; OrderedLocusNames=NP_0072A;
OS   Natronomonas pharaonis (strain ATCC 35678 / DSM 2160 / CIP 103997 / JCM
OS   8858 / NBRC 14720 / NCIMB 2260 / Gabara) (Halobacterium pharaonis).
OC   Archaea; Euryarchaeota; Stenosarchaea group; Halobacteria; Halobacteriales;
OC   Haloarculaceae; Natronomonas.
OX   NCBI_TaxID=348780;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 35678 / DSM 2160 / CIP 103997 / JCM 8858 / NBRC 14720 / NCIMB
RC   2260 / Gabara;
RX   PubMed=16169924; DOI=10.1101/gr.3952905;
RA   Falb M., Pfeiffer F., Palm P., Rodewald K., Hickmann V., Tittor J.,
RA   Oesterhelt D.;
RT   "Living with two extremes: conclusions from the genome sequence of
RT   Natronomonas pharaonis.";
RL   Genome Res. 15:1336-1343(2005).
CC   -!- FUNCTION: Catalyzes the CTP-dependent phosphorylation of riboflavin
CC       (vitamin B2) to form flavin mononucleotide (FMN). {ECO:0000250}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=CTP + riboflavin = CDP + FMN + H(+); Xref=Rhea:RHEA:25021,
CC         ChEBI:CHEBI:15378, ChEBI:CHEBI:37563, ChEBI:CHEBI:57986,
CC         ChEBI:CHEBI:58069, ChEBI:CHEBI:58210; EC=2.7.1.161;
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   -!- PATHWAY: Cofactor biosynthesis; FMN biosynthesis; FMN from riboflavin
CC       (CTP route): step 1/1.
CC   -!- SIMILARITY: Belongs to the archaeal riboflavin kinase family.
CC       {ECO:0000305}.
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DR   EMBL; CR936257; CAI48127.1; -; Genomic_DNA.
DR   RefSeq; WP_011321766.1; NC_007426.1.
DR   AlphaFoldDB; Q3IUQ3; -.
DR   SMR; Q3IUQ3; -.
DR   STRING; 348780.NP_0072A; -.
DR   EnsemblBacteria; CAI48127; CAI48127; NP_0072A.
DR   GeneID; 3700753; -.
DR   KEGG; nph:NP_0072A; -.
DR   eggNOG; arCOG01904; Archaea.
DR   HOGENOM; CLU_088476_0_0_2; -.
DR   OMA; AYYVRQY; -.
DR   OrthoDB; 91297at2157; -.
DR   UniPathway; UPA00276; UER00929.
DR   Proteomes; UP000002698; Chromosome.
DR   GO; GO:0000287; F:magnesium ion binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0000166; F:nucleotide binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0008531; F:riboflavin kinase activity; IEA:InterPro.
DR   GO; GO:0009398; P:FMN biosynthetic process; IEA:UniProtKB-UniRule.
DR   GO; GO:0016310; P:phosphorylation; IEA:UniProtKB-KW.
DR   GO; GO:0009231; P:riboflavin biosynthetic process; IEA:InterPro.
DR   CDD; cd00090; HTH_ARSR; 1.
DR   Gene3D; 1.10.10.10; -; 1.
DR   Gene3D; 2.40.30.30; -; 1.
DR   HAMAP; MF_01285; Riboflavin_kinase; 1.
DR   InterPro; IPR011991; ArsR-like_HTH.
DR   InterPro; IPR039063; RibK_CTP-dep.
DR   InterPro; IPR023470; Riboflavin_kinase_archaeal.
DR   InterPro; IPR023602; Riboflavin_kinase_CTP-dep.
DR   InterPro; IPR023465; Riboflavin_kinase_dom_sf.
DR   InterPro; IPR036388; WH-like_DNA-bd_sf.
DR   InterPro; IPR036390; WH_DNA-bd_sf.
DR   PANTHER; PTHR40706; PTHR40706; 1.
DR   Pfam; PF01982; CTP-dep_RFKase; 1.
DR   SUPFAM; SSF46785; SSF46785; 1.
DR   SUPFAM; SSF82114; SSF82114; 1.
PE   3: Inferred from homology;
KW   Flavoprotein; FMN; Kinase; Magnesium; Metal-binding; Nucleotide-binding;
KW   Reference proteome; Transferase.
FT   CHAIN           1..232
FT                   /note="Riboflavin kinase"
FT                   /id="PRO_0000322096"
FT   REGION          1..97
FT                   /note="H-T-H motif-like"
FT   REGION          98..232
FT                   /note="Riboflavin kinase"
FT   BINDING         107..112
FT                   /ligand="CDP"
FT                   /ligand_id="ChEBI:CHEBI:58069"
FT                   /evidence="ECO:0000250"
FT   BINDING         136
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000250"
FT   BINDING         138
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000250"
FT   BINDING         199
FT                   /ligand="FMN"
FT                   /ligand_id="ChEBI:CHEBI:58210"
FT                   /evidence="ECO:0000250"
FT   BINDING         207
FT                   /ligand="FMN"
FT                   /ligand_id="ChEBI:CHEBI:58210"
FT                   /evidence="ECO:0000250"
FT   BINDING         212..215
FT                   /ligand="CDP"
FT                   /ligand_id="ChEBI:CHEBI:58069"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   232 AA;  25603 MW;  7B9F4A021E05D190 CRC64;
     MSQTTERVGA DELSTLKLVA LDGALDGRVT VTCADLADRL DASNQTASRR LQRLEAAALV
     ERDMTGEGQR IAVTEAGERA LQREYADYRR LFEGDADVTL SGVVTSGMGE GRHYISLSGY
     MRQFRERLGY EPFPGTLNVD LDDGSVRTRA RMDALDPVKI DGWEDDERTY GPAFCWPAVL
     ETADGDRYGT AHVIAPERTH HGDDQLEIIA PEKLRETLSL DDGDTLSIHV SE