ID   BLVRB_LITCT             Reviewed;          24 AA.
AC   P55736;
DT   01-NOV-1997, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1997, sequence version 1.
DT   03-AUG-2022, entry version 58.
DE   RecName: Full=Flavin reductase (NADPH);
DE            Short=FR;
DE            EC=1.5.1.30;
DE   AltName: Full=NADPH-dehydrogenase;
DE   AltName: Full=NADPH-dependent diaphorase;
DE   AltName: Full=NADPH-methemoglobin reductase;
DE   Flags: Fragment;
OS   Lithobates catesbeianus (American bullfrog) (Rana catesbeiana).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Amphibia;
OC   Batrachia; Anura; Neobatrachia; Ranoidea; Ranidae; Lithobates.
OX   NCBI_TaxID=8400;
RN   [1]
RP   PROTEIN SEQUENCE, FUNCTION, SUBUNIT, CATALYTIC ACTIVITY, AND TISSUE
RP   SPECIFICITY.
RC   TISSUE=Erythrocyte;
RX   PubMed=2172227; DOI=10.1093/oxfordjournals.jbchem.a123190;
RA   Abe Y., Ito T., Okazaki T.;
RT   "Purification and characterization of NADPH-dependent methemoglobin
RT   reductase from the nucleated erythrocytes of bullfrog, Rana catesbeiana.";
RL   J. Biochem. 108:255-260(1990).
CC   -!- FUNCTION: Broad specificity oxidoreductase that catalyzes the NADPH-
CC       dependent reduction of a variety of flavins, such as riboflavin, FAD or
CC       FMN, methemoglobin and PQQ (pyrroloquinoline quinone). Contributes to
CC       heme catabolism and metabolizes linear tetrapyrroles (By similarity).
CC       {ECO:0000250, ECO:0000269|PubMed:2172227}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=NADP(+) + reduced riboflavin = 2 H(+) + NADPH + riboflavin;
CC         Xref=Rhea:RHEA:19377, ChEBI:CHEBI:15378, ChEBI:CHEBI:17607,
CC         ChEBI:CHEBI:57783, ChEBI:CHEBI:57986, ChEBI:CHEBI:58349; EC=1.5.1.30;
CC         Evidence={ECO:0000269|PubMed:2172227};
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       pH dependence:
CC         Optimum pH is 5.0 for NADPH-methemoglobin reductase activity, and 6.5
CC         for NADPH-diaphorase activity.;
CC   -!- SUBUNIT: Monomer. {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000250}.
CC   -!- TISSUE SPECIFICITY: Detected in erythrocytes (at protein level).
CC       {ECO:0000269|PubMed:2172227}.
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DR   PIR; PX0038; PX0038.
DR   AlphaFoldDB; P55736; -.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0042602; F:riboflavin reductase (NADPH) activity; IEA:UniProtKB-EC.
PE   1: Evidence at protein level;
KW   Cytoplasm; Direct protein sequencing; NADP; Oxidoreductase.
FT   CHAIN           1..>24
FT                   /note="Flavin reductase (NADPH)"
FT                   /id="PRO_0000064950"
FT   BINDING         9..14
FT                   /ligand="NADP(+)"
FT                   /ligand_id="ChEBI:CHEBI:58349"
FT                   /evidence="ECO:0000250"
FT   NON_TER         24
SQ   SEQUENCE   24 AA;  2417 MW;  7B6CD31436FAC4EC CRC64;
     APKNIVLFGA TGMTGQVTLG QALE