ID   DUSB_KLEPN              Reviewed;         321 AA.
AC   O52536;
DT   15-DEC-1998, integrated into UniProtKB/Swiss-Prot.
DT   01-JUN-1998, sequence version 1.
DT   03-AUG-2022, entry version 81.
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   Klebsiella pneumoniae.
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC   Enterobacteriaceae; Klebsiella/Raoultella group; Klebsiella.
OX   NCBI_TaxID=573;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RA   Beach M.B., Osuna R.;
RL   Submitted (DEC-1997) to the EMBL/GenBank/DDBJ databases.
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; AF040380; AAC77888.1; -; Genomic_DNA.
DR   AlphaFoldDB; O52536; -.
DR   SMR; O52536; -.
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..321
FT                   /note="tRNA-dihydrouridine synthase B"
FT                   /id="PRO_0000162090"
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   321 AA;  35804 MW;  06DF1A8B5C0B963C CRC64;
     MRIGHYQLRN RLIAAPMAGI TDRPFRTLCY EMGAGLTVSE MMSSNPQVWE SDKSRLRMVH
     VDEPGIRTVQ IAGSVPKEMA AAARINVESG AQIIDINMGC PAKKVNRKLA GSALLQYPDQ
     VKSILTAVVK AVDVPVTLKI RTGWEPEHRN CVEIAQLAEE CGIQALTIHG RTRACLFNGD
     AEYDSIRAVK QKVSIPVIAN GDITDPLKAR AVLDYTGADA LMIGRAAQGR PWIFREIQHY
     LDTGELLPPL PLAEVKRLLC AHVRELHGFY GQAKGYRIAR KHVSWYLQEH APDDQFRRTF
     NAIEDSSEQL EALEAYFENF A