ID Q0IAD2_SYNS3 Unreviewed; 556 AA.
AC Q0IAD2;
DT 03-OCT-2006, integrated into UniProtKB/TrEMBL.
DT 03-OCT-2006, sequence version 1.
DT 27-MAR-2024, entry version 126.
DE RecName: Full=Riboflavin biosynthesis protein RibBA {ECO:0000256|HAMAP-Rule:MF_01283};
DE Includes:
DE RecName: Full=3,4-dihydroxy-2-butanone 4-phosphate synthase {ECO:0000256|HAMAP-Rule:MF_01283};
DE Short=DHBP synthase {ECO:0000256|HAMAP-Rule:MF_01283};
DE EC=4.1.99.12 {ECO:0000256|HAMAP-Rule:MF_01283};
DE Includes:
DE RecName: Full=GTP cyclohydrolase-2 {ECO:0000256|HAMAP-Rule:MF_01283};
DE EC=3.5.4.25 {ECO:0000256|HAMAP-Rule:MF_01283};
DE AltName: Full=GTP cyclohydrolase II {ECO:0000256|HAMAP-Rule:MF_01283};
GN Name=ribAB {ECO:0000313|EMBL:ABI45687.1};
GN Synonyms=ribBA {ECO:0000256|HAMAP-Rule:MF_01283};
GN OrderedLocusNames=sync_1383 {ECO:0000313|EMBL:ABI45687.1};
OS Synechococcus sp. (strain CC9311).
OC Bacteria; Cyanobacteriota; Cyanophyceae; Synechococcales; Synechococcaceae;
OC Synechococcus.
OX NCBI_TaxID=64471 {ECO:0000313|EMBL:ABI45687.1, ECO:0000313|Proteomes:UP000001961};
RN [1] {ECO:0000313|EMBL:ABI45687.1, ECO:0000313|Proteomes:UP000001961}
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=CC9311 {ECO:0000313|EMBL:ABI45687.1,
RC ECO:0000313|Proteomes:UP000001961};
RX PubMed=16938853; DOI=10.1073/pnas.0602963103;
RA Palenik B., Ren Q., Dupont C.L., Myers G.S., Heidelberg J.F., Badger J.H.,
RA Madupu R., Nelson W.C., Brinkac L.M., Dodson R.J., Durkin A.S.,
RA Daugherty S.C., Sullivan S.A., Khouri H., Mohamoud Y., Halpin R.,
RA Paulsen I.T.;
RT "Genome sequence of Synechococcus CC9311: insights into adaptation to a
RT coastal environment.";
RL Proc. Natl. Acad. Sci. U.S.A. 103:13555-13559(2006).
CC -!- FUNCTION: Catalyzes the conversion of D-ribulose 5-phosphate to formate
CC and 3,4-dihydroxy-2-butanone 4-phosphate.
CC {ECO:0000256|ARBA:ARBA00002284, ECO:0000256|HAMAP-Rule:MF_01283}.
CC -!- FUNCTION: Catalyzes the conversion of GTP to 2,5-diamino-6-
CC ribosylamino-4(3H)-pyrimidinone 5'-phosphate (DARP), formate and
CC pyrophosphate. {ECO:0000256|HAMAP-Rule:MF_01283}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=D-ribulose 5-phosphate = (2S)-2-hydroxy-3-oxobutyl phosphate +
CC formate + H(+); Xref=Rhea:RHEA:18457, ChEBI:CHEBI:15378,
CC ChEBI:CHEBI:15740, ChEBI:CHEBI:58121, ChEBI:CHEBI:58830;
CC EC=4.1.99.12; Evidence={ECO:0000256|ARBA:ARBA00000141,
CC ECO:0000256|HAMAP-Rule:MF_01283};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=GTP + 4 H2O = 2,5-diamino-6-hydroxy-4-(5-phosphoribosylamino)-
CC pyrimidine + formate + 3 H(+) + 2 phosphate; Xref=Rhea:RHEA:23704,
CC ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:15740,
CC ChEBI:CHEBI:37565, ChEBI:CHEBI:43474, ChEBI:CHEBI:58614; EC=3.5.4.25;
CC Evidence={ECO:0000256|ARBA:ARBA00029293, ECO:0000256|HAMAP-
CC Rule:MF_01283};
CC -!- COFACTOR:
CC Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC Evidence={ECO:0000256|HAMAP-Rule:MF_01283};
CC Name=Mn(2+); Xref=ChEBI:CHEBI:29035;
CC Evidence={ECO:0000256|HAMAP-Rule:MF_01283};
CC Note=Binds 2 divalent metal cations per subunit. Magnesium or
CC manganese. {ECO:0000256|HAMAP-Rule:MF_01283};
CC -!- COFACTOR:
CC Name=Mn(2+); Xref=ChEBI:CHEBI:29035;
CC Evidence={ECO:0000256|ARBA:ARBA00001936};
CC -!- COFACTOR:
CC Name=Zn(2+); Xref=ChEBI:CHEBI:29105;
CC Evidence={ECO:0000256|HAMAP-Rule:MF_01283};
CC Note=Binds 1 zinc ion per subunit. {ECO:0000256|HAMAP-Rule:MF_01283};
CC -!- PATHWAY: Cofactor biosynthesis; riboflavin biosynthesis; 2-hydroxy-3-
CC oxobutyl phosphate from D-ribulose 5-phosphate: step 1/1.
CC {ECO:0000256|ARBA:ARBA00004904, ECO:0000256|HAMAP-Rule:MF_01283}.
CC -!- PATHWAY: Cofactor biosynthesis; riboflavin biosynthesis; 5-amino-6-(D-
CC ribitylamino)uracil from GTP: step 1/4. {ECO:0000256|ARBA:ARBA00004853,
CC ECO:0000256|HAMAP-Rule:MF_01283}.
CC -!- SIMILARITY: In the C-terminal section; belongs to the GTP
CC cyclohydrolase II family. {ECO:0000256|HAMAP-Rule:MF_01283}.
CC -!- SIMILARITY: In the N-terminal section; belongs to the DHBP synthase
CC family. {ECO:0000256|ARBA:ARBA00005520, ECO:0000256|HAMAP-
CC Rule:MF_01283}.
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DR EMBL; CP000435; ABI45687.1; -; Genomic_DNA.
DR AlphaFoldDB; Q0IAD2; -.
DR STRING; 64471.sync_1383; -.
DR KEGG; syg:sync_1383; -.
DR eggNOG; COG0108; Bacteria.
DR eggNOG; COG0807; Bacteria.
DR HOGENOM; CLU_020273_0_1_3; -.
DR OrthoDB; 9793111at2; -.
DR UniPathway; UPA00275; UER00399.
DR Proteomes; UP000001961; Chromosome.
DR GO; GO:0008686; F:3,4-dihydroxy-2-butanone-4-phosphate synthase activity; IEA:UniProtKB-UniRule.
DR GO; GO:0005525; F:GTP binding; IEA:UniProtKB-KW.
DR GO; GO:0003935; F:GTP cyclohydrolase II activity; IEA:UniProtKB-UniRule.
DR GO; GO:0000287; F:magnesium ion binding; IEA:UniProtKB-UniRule.
DR GO; GO:0030145; F:manganese ion binding; IEA:UniProtKB-UniRule.
DR GO; GO:0008270; F:zinc ion binding; IEA:UniProtKB-UniRule.
DR GO; GO:0009231; P:riboflavin biosynthetic process; IEA:UniProtKB-UniRule.
DR CDD; cd00641; GTP_cyclohydro2; 1.
DR Gene3D; 3.90.870.10; DHBP synthase; 1.
DR Gene3D; 3.40.50.10990; GTP cyclohydrolase II; 1.
DR HAMAP; MF_00179; RibA; 1.
DR HAMAP; MF_00180; RibB; 1.
DR HAMAP; MF_01283; RibBA; 1.
DR InterPro; IPR017945; DHBP_synth_RibB-like_a/b_dom.
DR InterPro; IPR000422; DHBP_synthase_RibB.
DR InterPro; IPR032677; GTP_cyclohydro_II.
DR InterPro; IPR000926; RibA.
DR InterPro; IPR036144; RibA-like_sf.
DR InterPro; IPR016299; Riboflavin_synth_RibBA.
DR NCBIfam; TIGR00505; ribA; 1.
DR NCBIfam; TIGR00506; ribB; 1.
DR PANTHER; PTHR21327; GTP CYCLOHYDROLASE II-RELATED; 1.
DR PANTHER; PTHR21327:SF48; RIBOFLAVIN BIOSYNTHESIS PROTEIN RIBBA; 1.
DR Pfam; PF00926; DHBP_synthase; 1.
DR Pfam; PF00925; GTP_cyclohydro2; 1.
DR SUPFAM; SSF142695; RibA-like; 1.
DR SUPFAM; SSF55821; YrdC/RibB; 1.
PE 3: Inferred from homology;
KW GTP-binding {ECO:0000256|ARBA:ARBA00023134, ECO:0000256|HAMAP-
KW Rule:MF_01283};
KW Hydrolase {ECO:0000256|ARBA:ARBA00022801, ECO:0000256|HAMAP-Rule:MF_01283};
KW Lyase {ECO:0000256|ARBA:ARBA00023239, ECO:0000256|HAMAP-Rule:MF_01283};
KW Magnesium {ECO:0000256|ARBA:ARBA00022842, ECO:0000256|HAMAP-Rule:MF_01283};
KW Manganese {ECO:0000256|ARBA:ARBA00023211, ECO:0000256|HAMAP-Rule:MF_01283};
KW Metal-binding {ECO:0000256|ARBA:ARBA00022723, ECO:0000256|HAMAP-
KW Rule:MF_01283};
KW Multifunctional enzyme {ECO:0000256|ARBA:ARBA00023268, ECO:0000256|HAMAP-
KW Rule:MF_01283};
KW Nucleotide-binding {ECO:0000256|ARBA:ARBA00022741, ECO:0000256|HAMAP-
KW Rule:MF_01283}; Reference proteome {ECO:0000313|Proteomes:UP000001961};
KW Riboflavin biosynthesis {ECO:0000256|ARBA:ARBA00022619, ECO:0000256|HAMAP-
KW Rule:MF_01283}; Zinc {ECO:0000256|HAMAP-Rule:MF_01283}.
FT DOMAIN 232..398
FT /note="GTP cyclohydrolase II"
FT /evidence="ECO:0000259|Pfam:PF00925"
FT REGION 1..225
FT /note="DHBP synthase"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01283"
FT REGION 226..556
FT /note="GTP cyclohydrolase II"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01283"
FT ACT_SITE 354
FT /note="Proton acceptor; for GTP cyclohydrolase activity"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01283"
FT ACT_SITE 356
FT /note="Nucleophile; for GTP cyclohydrolase activity"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01283"
FT BINDING 49..50
FT /ligand="D-ribulose 5-phosphate"
FT /ligand_id="ChEBI:CHEBI:58121"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01283"
FT BINDING 50
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="2"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01283"
FT BINDING 50
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="1"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01283"
FT BINDING 54
FT /ligand="D-ribulose 5-phosphate"
FT /ligand_id="ChEBI:CHEBI:58121"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01283"
FT BINDING 164..168
FT /ligand="D-ribulose 5-phosphate"
FT /ligand_id="ChEBI:CHEBI:58121"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01283"
FT BINDING 167
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="2"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01283"
FT BINDING 188
FT /ligand="D-ribulose 5-phosphate"
FT /ligand_id="ChEBI:CHEBI:58121"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01283"
FT BINDING 277..281
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01283"
FT BINDING 282
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01283"
FT BINDING 293
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01283"
FT BINDING 295
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01283"
FT BINDING 298
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01283"
FT BINDING 320..322
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01283"
FT BINDING 342
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01283"
FT BINDING 377
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01283"
FT BINDING 382
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01283"
FT SITE 150
FT /note="Essential for DHBP synthase activity"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01283"
FT SITE 188
FT /note="Essential for DHBP synthase activity"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01283"
SQ SEQUENCE 556 AA; 61226 MW; 0B926E6D5D7789E0 CRC64;
MMRACWIPRT LSHSAVASES MDPIFDSIPD ALNAIRNGEC VVVVDDERRE NEGDLICASQ
FATPEQINFM AKEARGLICL AIEGDRLDAL DLPLMVDRNT DENQTAFTVS IDAGPEHGVS
TGISAEDRSR TIQVVLQADA KPSDLRRPGH VFPLRARSGG VLKRAGHTEA AVDLAQLAGL
IPSGVICEIQ NSDGSMARLP ELQNYSKQFG LRLISIADLI SYRLQNERFV RRHAQCVMPS
RFGQFQAIGF RNELDNSEHV ALVKGVPGQL QEPVLVRMHS ECLTGDSFGS LRCDCGPQLE
AALSQIEQEG EGVVVYLKQE GRGIGLINKL KAYSLQDGGL DTVEANEKLG FGADLRNYGV
GAQILGDLGI HRLRLLTNNP RKIAGLGGYG LEVVSRVPLI INPGDHNANY LATKRDKLGH
LFNEYNAAEI ATLAWDCGEE FIAKLPDLLH RAEALAVKSS LTLQAEQTPR LLALWERPQF
VWTVSGETSA IELFLKTLAS WTETKRLGFL KTAKAEQRLH PSLQLNREER DLASLLSDKK
NSWSDESDQP ILIHWS
//
