RISB2_BRUAB
ID RISB2_BRUAB Reviewed; 158 AA.
AC P61711; Q44668; Q578I1;
DT 07-JUN-2004, integrated into UniProtKB/Swiss-Prot.
DT 07-JUN-2004, sequence version 1.
DT 03-AUG-2022, entry version 106.
DE RecName: Full=6,7-dimethyl-8-ribityllumazine synthase 2 {ECO:0000255|HAMAP-Rule:MF_00178};
DE Short=DMRL synthase 2 {ECO:0000255|HAMAP-Rule:MF_00178};
DE Short=LS 2 {ECO:0000255|HAMAP-Rule:MF_00178};
DE Short=Lumazine synthase 2 {ECO:0000255|HAMAP-Rule:MF_00178};
DE EC=2.5.1.78 {ECO:0000255|HAMAP-Rule:MF_00178};
DE AltName: Full=BLS {ECO:0000250|UniProtKB:Q2YKV1};
DE AltName: Full=Type II lumazine synthase {ECO:0000250|UniProtKB:Q2YKV1};
GN Name=ribH2; Synonyms=ribH, ribH-2; OrderedLocusNames=BruAb2_0535;
OS Brucella abortus biovar 1 (strain 9-941).
OC Bacteria; Proteobacteria; Alphaproteobacteria; Hyphomicrobiales;
OC Brucellaceae; Brucella/Ochrobactrum group; Brucella.
OX NCBI_TaxID=262698;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=7664168; DOI=10.1128/cdli.2.3.263-267.1995;
RA Hemmen F., Weynants V., Scarcez T., Letesson J.-J., Saman E.;
RT "Cloning and sequence analysis of a newly identified Brucella abortus gene
RT and serological evaluation of the 17-kilodalton antigen that it encodes.";
RL Clin. Diagn. Lab. Immunol. 2:263-267(1995).
RN [2]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=9-941;
RX PubMed=15805518; DOI=10.1128/jb.187.8.2715-2726.2005;
RA Halling S.M., Peterson-Burch B.D., Bricker B.J., Zuerner R.L., Qing Z.,
RA Li L.-L., Kapur V., Alt D.P., Olsen S.C.;
RT "Completion of the genome sequence of Brucella abortus and comparison to
RT the highly similar genomes of Brucella melitensis and Brucella suis.";
RL J. Bacteriol. 187:2715-2726(2005).
CC -!- FUNCTION: Catalyzes the formation of 6,7-dimethyl-8-ribityllumazine by
CC condensation of 5-amino-6-(D-ribitylamino)uracil with 3,4-dihydroxy-2-
CC butanone 4-phosphate. This is the penultimate step in the biosynthesis
CC of riboflavin. Displays low catalytic activity in comparison with the
CC isozyme RibH1. Is a highly immunogenic protein. Activates dendritic
CC cells (DCs) in vitro, increasing the levels of costimulatory molecules
CC and the secretion of pro-inflammatory cytokines, and recruits DCs, B
CC cells and CD8+ T cells in vivo, both effects in a TLR4-dependent
CC manner. Induces the cross presentation of covalently attached peptides
CC and generates a strong and long-lasting humoral immune response without
CC adjuvants; TLR4 signaling is necessary for the induction of the
CC cytotoxic response but not for antigen cross presentation. Elicits a
CC TLR4-mediated protective response against B16 melanoma in mice, slowing
CC tumor growth and prolonging mice survival.
CC {ECO:0000250|UniProtKB:Q2YKV1}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=(2S)-2-hydroxy-3-oxobutyl phosphate + 5-amino-6-(D-
CC ribitylamino)uracil = 6,7-dimethyl-8-(1-D-ribityl)lumazine + H(+) + 2
CC H2O + phosphate; Xref=Rhea:RHEA:26152, ChEBI:CHEBI:15377,
CC ChEBI:CHEBI:15378, ChEBI:CHEBI:15934, ChEBI:CHEBI:43474,
CC ChEBI:CHEBI:58201, ChEBI:CHEBI:58830; EC=2.5.1.78;
CC Evidence={ECO:0000255|HAMAP-Rule:MF_00178};
CC -!- PATHWAY: Cofactor biosynthesis; riboflavin biosynthesis; riboflavin
CC from 2-hydroxy-3-oxobutyl phosphate and 5-amino-6-(D-
CC ribitylamino)uracil: step 1/2. {ECO:0000255|HAMAP-Rule:MF_00178}.
CC -!- SUBUNIT: Homodecamer, arranged as a dimer of pentamers.
CC {ECO:0000250|UniProtKB:Q2YKV1}.
CC -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000250|UniProtKB:Q2YKV1}.
CC -!- INDUCTION: The two ribH genes may be differentially expressed during
CC the Brucella infection cycle. Brucella would use RibH1 for flavin
CC biosynthesis during the extracellular phase and RibH2 during
CC intracellular growth. {ECO:0000250|UniProtKB:Q2YKV1}.
CC -!- BIOTECHNOLOGY: Could be useful as a specific antigen for the
CC serological diagnosis of active infection of both human and bovine
CC brucellosis. Has been used as a protein carrier of foreign peptides and
CC proteins. The described characteristics of BLS make this protein an
CC ideal antigen carrier for vaccine development. The antitumor effect of
CC BLS could lead to a therapeutic strategy utilizing a TLR4 ligand; as
CC the expression of TLR4 has been reported on a large number of tumors,
CC BLS signaling via TLR4 could make a notable contribution to the success
CC of cancer treatment when coadministered with other cancer vaccines or
CC treatments like radiation or chemotherapy.
CC {ECO:0000250|UniProtKB:Q2YKV1}.
CC -!- SIMILARITY: Belongs to the DMRL synthase family. {ECO:0000255|HAMAP-
CC Rule:MF_00178}.
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DR EMBL; Z46864; CAA86936.1; -; Genomic_DNA.
DR EMBL; AE017224; AAX75953.1; -; Genomic_DNA.
DR PIR; S49918; S49918.
DR RefSeq; WP_002965946.1; NC_006933.1.
DR AlphaFoldDB; P61711; -.
DR SMR; P61711; -.
DR EnsemblBacteria; AAX75953; AAX75953; BruAb2_0535.
DR GeneID; 45126031; -.
DR GeneID; 55592351; -.
DR KEGG; bmb:BruAb2_0535; -.
DR HOGENOM; CLU_089358_0_0_5; -.
DR OMA; PHHFHEH; -.
DR BRENDA; 2.5.1.78; 994.
DR UniPathway; UPA00275; UER00404.
DR EvolutionaryTrace; P61711; -.
DR PRO; PR:P61711; -.
DR Proteomes; UP000000540; Chromosome II.
DR GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR GO; GO:0009349; C:riboflavin synthase complex; IEA:InterPro.
DR GO; GO:0000906; F:6,7-dimethyl-8-ribityllumazine synthase activity; IEA:UniProtKB-UniRule.
DR GO; GO:0009231; P:riboflavin biosynthetic process; IEA:UniProtKB-UniRule.
DR Gene3D; 3.40.50.960; -; 1.
DR HAMAP; MF_00178; Lumazine_synth; 1.
DR InterPro; IPR034964; LS.
DR InterPro; IPR002180; LS/RS.
DR InterPro; IPR036467; LS/RS_sf.
DR PANTHER; PTHR21058; PTHR21058; 1.
DR Pfam; PF00885; DMRL_synthase; 1.
DR SUPFAM; SSF52121; SSF52121; 1.
PE 3: Inferred from homology;
KW Cytoplasm; Riboflavin biosynthesis; Transferase.
FT CHAIN 1..158
FT /note="6,7-dimethyl-8-ribityllumazine synthase 2"
FT /id="PRO_0000134725"
FT ACT_SITE 86
FT /note="Proton donor"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT BINDING 20
FT /ligand="5-amino-6-(D-ribitylamino)uracil"
FT /ligand_id="ChEBI:CHEBI:15934"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT BINDING 54..56
FT /ligand="5-amino-6-(D-ribitylamino)uracil"
FT /ligand_id="ChEBI:CHEBI:15934"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT BINDING 78..80
FT /ligand="5-amino-6-(D-ribitylamino)uracil"
FT /ligand_id="ChEBI:CHEBI:15934"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT BINDING 111
FT /ligand="5-amino-6-(D-ribitylamino)uracil"
FT /ligand_id="ChEBI:CHEBI:15934"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT BINDING 125
FT /ligand="(2S)-2-hydroxy-3-oxobutyl phosphate"
FT /ligand_id="ChEBI:CHEBI:58830"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
SQ SEQUENCE 158 AA; 17356 MW; EE59C2C815E53A2B CRC64;
MNQSCPNKTS FKIAFIQARW HADIVDEARK SFVAELAAKT GGSVEVEIFD VPGAYEIPLH
AKTLARTGRY AAIVGAAFVI DGGIYRHDFV ATAVINGMMQ VQLETEVPVL SVVLTPHHFH
ESKEHHDFFH AHFKVKGVEA AHAALQIVSE RSRIAALV
