ID   DYR9_ECOLX              Reviewed;         177 AA.
AC   Q59397;
DT   01-NOV-1997, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1996, sequence version 1.
DT   25-MAY-2022, entry version 83.
DE   RecName: Full=Dihydrofolate reductase type 9;
DE            EC=1.5.1.3;
DE   AltName: Full=Dihydrofolate reductase type IX;
GN   Name=dhfrIX;
OS   Escherichia coli.
OG   Plasmid pCJOO1.
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC   Enterobacteriaceae; Escherichia.
OX   NCBI_TaxID=562;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], AND FUNCTION.
RC   STRAIN=3926;
RX   PubMed=1659308; DOI=10.1128/aac.35.9.1891;
RA   Jansson C., Skoeld O.;
RT   "Appearance of a new trimethoprim resistance gene, dhfrIX, in Escherichia
RT   coli from swine.";
RL   Antimicrob. Agents Chemother. 35:1891-1899(1991).
CC   -!- FUNCTION: Key enzyme in folate metabolism. Catalyzes an essential
CC       reaction for de novo glycine and purine synthesis, and for DNA
CC       precursor synthesis (By similarity). {ECO:0000250,
CC       ECO:0000269|PubMed:1659308}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=(6S)-5,6,7,8-tetrahydrofolate + NADP(+) = 7,8-dihydrofolate +
CC         H(+) + NADPH; Xref=Rhea:RHEA:15009, ChEBI:CHEBI:15378,
CC         ChEBI:CHEBI:57451, ChEBI:CHEBI:57453, ChEBI:CHEBI:57783,
CC         ChEBI:CHEBI:58349; EC=1.5.1.3; Evidence={ECO:0000255|PROSITE-
CC         ProRule:PRU00660};
CC   -!- PATHWAY: Cofactor biosynthesis; tetrahydrofolate biosynthesis; 5,6,7,8-
CC       tetrahydrofolate from 7,8-dihydrofolate: step 1/1.
CC   -!- SUBUNIT: Homodimer. {ECO:0000250}.
CC   -!- MISCELLANEOUS: Confers trimethoprim resistance.
CC       {ECO:0000269|PubMed:1659308}.
CC   -!- SIMILARITY: Belongs to the dihydrofolate reductase family.
CC       {ECO:0000305}.
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DR   EMBL; X57730; CAA40897.1; -; Genomic_DNA.
DR   PIR; A49788; A49788.
DR   RefSeq; WP_063844475.1; NG_047742.1.
DR   AlphaFoldDB; Q59397; -.
DR   SMR; Q59397; -.
DR   KEGG; ag:CAA40897; -.
DR   UniPathway; UPA00077; UER00158.
DR   GO; GO:0004146; F:dihydrofolate reductase activity; IEA:UniProtKB-EC.
DR   GO; GO:0050661; F:NADP binding; IEA:InterPro.
DR   GO; GO:0006545; P:glycine biosynthetic process; IEA:InterPro.
DR   GO; GO:0006730; P:one-carbon metabolic process; IEA:UniProtKB-KW.
DR   GO; GO:0046677; P:response to antibiotic; IEA:UniProtKB-KW.
DR   GO; GO:0031427; P:response to methotrexate; IEA:UniProtKB-KW.
DR   GO; GO:0046654; P:tetrahydrofolate biosynthetic process; IEA:UniProtKB-UniPathway.
DR   CDD; cd00209; DHFR; 1.
DR   Gene3D; 3.40.430.10; -; 1.
DR   InterPro; IPR012259; DHFR.
DR   InterPro; IPR024072; DHFR-like_dom_sf.
DR   InterPro; IPR017925; DHFR_CS.
DR   InterPro; IPR001796; DHFR_dom.
DR   PANTHER; PTHR48069; PTHR48069; 1.
DR   Pfam; PF00186; DHFR_1; 1.
DR   SUPFAM; SSF53597; SSF53597; 1.
DR   PROSITE; PS00075; DHFR_1; 1.
DR   PROSITE; PS51330; DHFR_2; 1.
PE   3: Inferred from homology;
KW   Antibiotic resistance; Methotrexate resistance; NADP;
KW   One-carbon metabolism; Oxidoreductase; Plasmid; Trimethoprim resistance.
FT   CHAIN           1..177
FT                   /note="Dihydrofolate reductase type 9"
FT                   /id="PRO_0000186427"
FT   DOMAIN          3..167
FT                   /note="DHFR"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00660"
SQ   SEQUENCE   177 AA;  19879 MW;  F478DBA8E745ABD0 CRC64;
     MASLNMIVAV NKTGGIGFEN QIPWHEPEDL KHFKAVTMNS VLIMGRKTFA SLPKVLPGRL
     HVVVSKTVPP TQNTDQVVYV STYQIAVRTA SLLVDKPEYS QIFVIGGKSA YENLAAYVDK
     LYLTRVQLNT QQDTELDLSL FKSWKLVSEV PTITENKTKL IFQIWINPNP ISEEPTC