ID   DUSB_PROVU              Reviewed;         323 AA.
AC   O52533;
DT   28-NOV-2003, integrated into UniProtKB/Swiss-Prot.
DT   01-JAN-1999, sequence version 2.
DT   03-AUG-2022, entry version 80.
DE   RecName: Full=tRNA-dihydrouridine synthase B {ECO:0000255|HAMAP-Rule:MF_02042};
DE            EC=1.3.1.- {ECO:0000255|HAMAP-Rule:MF_02042};
GN   Name=dusB {ECO:0000255|HAMAP-Rule:MF_02042};
OS   Proteus vulgaris.
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC   Morganellaceae; Proteus.
OX   NCBI_TaxID=585;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=9811652; DOI=10.1128/jb.180.22.5932-5946.1998;
RA   Beach M.B., Osuna R.;
RT   "Identification and characterization of the fis operon in enteric
RT   bacteria.";
RL   J. Bacteriol. 180:5932-5946(1998).
CC   -!- FUNCTION: Catalyzes the synthesis of 5,6-dihydrouridine (D), a modified
CC       base found in the D-loop of most tRNAs, via the reduction of the C5-C6
CC       double bond in target uridines. {ECO:0000255|HAMAP-Rule:MF_02042}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=a 5,6-dihydrouridine in tRNA + NAD(+) = a uridine in tRNA +
CC         H(+) + NADH; Xref=Rhea:RHEA:54452, Rhea:RHEA-COMP:13339, Rhea:RHEA-
CC         COMP:13887, ChEBI:CHEBI:15378, ChEBI:CHEBI:57540, ChEBI:CHEBI:57945,
CC         ChEBI:CHEBI:65315, ChEBI:CHEBI:74443; Evidence={ECO:0000255|HAMAP-
CC         Rule:MF_02042};
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=a 5,6-dihydrouridine in tRNA + NADP(+) = a uridine in tRNA +
CC         H(+) + NADPH; Xref=Rhea:RHEA:23624, Rhea:RHEA-COMP:13339, Rhea:RHEA-
CC         COMP:13887, ChEBI:CHEBI:15378, ChEBI:CHEBI:57783, ChEBI:CHEBI:58349,
CC         ChEBI:CHEBI:65315, ChEBI:CHEBI:74443; Evidence={ECO:0000255|HAMAP-
CC         Rule:MF_02042};
CC   -!- COFACTOR:
CC       Name=FMN; Xref=ChEBI:CHEBI:58210;
CC         Evidence={ECO:0000255|HAMAP-Rule:MF_02042};
CC   -!- SIMILARITY: Belongs to the Dus family. DusB subfamily.
CC       {ECO:0000255|HAMAP-Rule:MF_02042}.
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DR   EMBL; AF040379; AAC77884.1; -; Genomic_DNA.
DR   RefSeq; WP_072063792.1; NZ_CVRY01000003.1.
DR   AlphaFoldDB; O52533; -.
DR   SMR; O52533; -.
DR   STRING; 585.DR95_2014; -.
DR   eggNOG; COG0042; Bacteria.
DR   GO; GO:0050660; F:flavin adenine dinucleotide binding; IEA:InterPro.
DR   GO; GO:0010181; F:FMN binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0000049; F:tRNA binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0017150; F:tRNA dihydrouridine synthase activity; IEA:UniProtKB-UniRule.
DR   CDD; cd02801; DUS_like_FMN; 1.
DR   Gene3D; 1.10.1200.80; -; 1.
DR   Gene3D; 3.20.20.70; -; 1.
DR   HAMAP; MF_02042; DusB_subfam; 1.
DR   InterPro; IPR013785; Aldolase_TIM.
DR   InterPro; IPR035587; DUS-like_FMN-bd.
DR   InterPro; IPR001269; DUS_fam.
DR   InterPro; IPR032887; DusB.
DR   InterPro; IPR024036; tRNA-dHydroUridine_Synthase_C.
DR   InterPro; IPR004652; tRNA_dU_NifR3.
DR   InterPro; IPR018517; tRNA_hU_synthase_CS.
DR   Pfam; PF01207; Dus; 1.
DR   PIRSF; PIRSF006621; Dus; 1.
DR   TIGRFAMs; TIGR00737; nifR3_yhdG; 1.
DR   PROSITE; PS01136; UPF0034; 1.
PE   3: Inferred from homology;
KW   Flavoprotein; FMN; NADP; Oxidoreductase; RNA-binding; tRNA processing;
KW   tRNA-binding.
FT   CHAIN           1..323
FT                   /note="tRNA-dihydrouridine synthase B"
FT                   /id="PRO_0000162092"
FT   ACT_SITE        100
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_02042"
FT   BINDING         16..18
FT                   /ligand="FMN"
FT                   /ligand_id="ChEBI:CHEBI:58210"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_02042"
FT   BINDING         70
FT                   /ligand="FMN"
FT                   /ligand_id="ChEBI:CHEBI:58210"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_02042"
FT   BINDING         139
FT                   /ligand="FMN"
FT                   /ligand_id="ChEBI:CHEBI:58210"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_02042"
FT   BINDING         200..202
FT                   /ligand="FMN"
FT                   /ligand_id="ChEBI:CHEBI:58210"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_02042"
FT   BINDING         224..225
FT                   /ligand="FMN"
FT                   /ligand_id="ChEBI:CHEBI:58210"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_02042"
SQ   SEQUENCE   323 AA;  35923 MW;  E81F3C4365E07285 CRC64;
     MRIGQYQLKN CLIAAPMAGV TDRPFRSLCY DMGAGMTVSE MLSSNPQVWQ TDKSRLRMVH
     SDELGIRSVQ IAGSDPVDMA AAAKINADSG AQIIDINMGC PAKKVNKKLA GSALLRHPDL
     VAEILSAVVN AVDVPVTLKI RTGWSPDERN CVEIAKLAER CGIQALTIHG RTRECLFKGE
     AEYDSIRTVK QNVSIPIIAN GDITDPLKAR AVLDYTGADA LMIGRAAQGR PWIFREIQHY
     LDTGELLPPL PIAEVQQIMQ KHVRELHDFY GQGKGTRIAR KHVSWYLKEH APDDQFRRSF
     NAIEDASEQL EALEAYFENF LRK