ID   FOLD_HALWD              Reviewed;         311 AA.
AC   Q18GK1;
DT   12-DEC-2006, integrated into UniProtKB/Swiss-Prot.
DT   25-JUL-2006, sequence version 1.
DT   03-AUG-2022, entry version 96.
DE   RecName: Full=Bifunctional protein FolD {ECO:0000255|HAMAP-Rule:MF_01576};
DE   Includes:
DE     RecName: Full=Methylenetetrahydrofolate dehydrogenase {ECO:0000255|HAMAP-Rule:MF_01576};
DE              EC=1.5.1.5 {ECO:0000255|HAMAP-Rule:MF_01576};
DE   Includes:
DE     RecName: Full=Methenyltetrahydrofolate cyclohydrolase {ECO:0000255|HAMAP-Rule:MF_01576};
DE              EC=3.5.4.9 {ECO:0000255|HAMAP-Rule:MF_01576};
GN   Name=folD {ECO:0000255|HAMAP-Rule:MF_01576}; OrderedLocusNames=HQ_2790A;
OS   Haloquadratum walsbyi (strain DSM 16790 / HBSQ001).
OC   Archaea; Euryarchaeota; Stenosarchaea group; Halobacteria; Haloferacales;
OC   Haloferacaceae; Haloquadratum.
OX   NCBI_TaxID=362976;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=DSM 16790 / HBSQ001;
RX   PubMed=16820047; DOI=10.1186/1471-2164-7-169;
RA   Bolhuis H., Palm P., Wende A., Falb M., Rampp M., Rodriguez-Valera F.,
RA   Pfeiffer F., Oesterhelt D.;
RT   "The genome of the square archaeon Haloquadratum walsbyi: life at the
RT   limits of water activity.";
RL   BMC Genomics 7:169-169(2006).
CC   -!- FUNCTION: Catalyzes the oxidation of 5,10-methylenetetrahydrofolate to
CC       5,10-methenyltetrahydrofolate and then the hydrolysis of 5,10-
CC       methenyltetrahydrofolate to 10-formyltetrahydrofolate.
CC       {ECO:0000255|HAMAP-Rule:MF_01576}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=(6R)-5,10-methylene-5,6,7,8-tetrahydrofolate + NADP(+) = 5,10-
CC         methenyltetrahydrofolate + NADPH; Xref=Rhea:RHEA:22812,
CC         ChEBI:CHEBI:15636, ChEBI:CHEBI:57455, ChEBI:CHEBI:57783,
CC         ChEBI:CHEBI:58349; EC=1.5.1.5; Evidence={ECO:0000255|HAMAP-
CC         Rule:MF_01576};
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=5,10-methenyltetrahydrofolate + H2O = (6S)-10-
CC         formyltetrahydrofolate + H(+); Xref=Rhea:RHEA:23700,
CC         ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:57454,
CC         ChEBI:CHEBI:57455; EC=3.5.4.9; Evidence={ECO:0000255|HAMAP-
CC         Rule:MF_01576};
CC   -!- PATHWAY: One-carbon metabolism; tetrahydrofolate interconversion.
CC       {ECO:0000255|HAMAP-Rule:MF_01576}.
CC   -!- SUBUNIT: Homodimer. {ECO:0000255|HAMAP-Rule:MF_01576}.
CC   -!- SIMILARITY: Belongs to the tetrahydrofolate
CC       dehydrogenase/cyclohydrolase family. {ECO:0000255|HAMAP-Rule:MF_01576}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   EMBL; AM180088; CAJ52897.1; -; Genomic_DNA.
DR   RefSeq; WP_011572010.1; NC_008212.1.
DR   AlphaFoldDB; Q18GK1; -.
DR   SMR; Q18GK1; -.
DR   STRING; 362976.HQ_2790A; -.
DR   EnsemblBacteria; CAJ52897; CAJ52897; HQ_2790A.
DR   GeneID; 4193993; -.
DR   KEGG; hwa:HQ_2790A; -.
DR   eggNOG; arCOG04538; Archaea.
DR   HOGENOM; CLU_034045_1_2_2; -.
DR   OMA; HIVGRPM; -.
DR   UniPathway; UPA00193; -.
DR   Proteomes; UP000001975; Chromosome.
DR   GO; GO:0004477; F:methenyltetrahydrofolate cyclohydrolase activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0004488; F:methylenetetrahydrofolate dehydrogenase (NADP+) activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0000105; P:histidine biosynthetic process; IEA:UniProtKB-KW.
DR   GO; GO:0009086; P:methionine biosynthetic process; IEA:UniProtKB-KW.
DR   GO; GO:0006164; P:purine nucleotide biosynthetic process; IEA:UniProtKB-KW.
DR   GO; GO:0035999; P:tetrahydrofolate interconversion; IEA:UniProtKB-UniPathway.
DR   CDD; cd01080; NAD_bind_m-THF_DH_Cyclohyd; 1.
DR   HAMAP; MF_01576; THF_DHG_CYH; 1.
DR   InterPro; IPR046346; Aminiacid_DH-like_N_sf.
DR   InterPro; IPR036291; NAD(P)-bd_dom_sf.
DR   InterPro; IPR000672; THF_DH/CycHdrlase.
DR   InterPro; IPR020630; THF_DH/CycHdrlase_cat_dom.
DR   InterPro; IPR020631; THF_DH/CycHdrlase_NAD-bd_dom.
DR   Pfam; PF00763; THF_DHG_CYH; 1.
DR   Pfam; PF02882; THF_DHG_CYH_C; 1.
DR   PRINTS; PR00085; THFDHDRGNASE.
DR   SUPFAM; SSF51735; SSF51735; 1.
DR   SUPFAM; SSF53223; SSF53223; 1.
PE   3: Inferred from homology;
KW   Amino-acid biosynthesis; Histidine biosynthesis; Hydrolase;
KW   Methionine biosynthesis; Multifunctional enzyme; NADP;
KW   One-carbon metabolism; Oxidoreductase; Purine biosynthesis;
KW   Reference proteome.
FT   CHAIN           1..311
FT                   /note="Bifunctional protein FolD"
FT                   /id="PRO_0000268581"
FT   BINDING         180..182
FT                   /ligand="NADP(+)"
FT                   /ligand_id="ChEBI:CHEBI:58349"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01576"
FT   BINDING         209
FT                   /ligand="NADP(+)"
FT                   /ligand_id="ChEBI:CHEBI:58349"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01576"
FT   BINDING         250
FT                   /ligand="NADP(+)"
FT                   /ligand_id="ChEBI:CHEBI:58349"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01576"
SQ   SEQUENCE   311 AA;  33157 MW;  786986C9779615B3 CRC64;
     MRFKYVASKY SCVTQTQTQL IDGTEVAASI RSDLISSVTR IVNTGTTPQL ATVLMNDDPA
     SQTYVSMKHD DCEEVGIATR DITIDPEAPA AELFDTVDEL NADSSVHGIL VQMPLPDHVD
     EREVLRRIDP KKDVDGFHPE NVGRLVAGQP RYKPCTPHGI QKLLIAADIE TEGANAVVIG
     RSNIVGKPMA NLLIQKADAG NATVTTCHSR TNNLASKTRD ADIIIAAAGV PEMIDGDMIS
     TGTVVIDVGI NRVETENGSE LVGDVEFESA AKKADAITPV PGGVGPMTRA MLLWNTVKAT
     AIATDTSIEL P