ID   PANB_BACC1              Reviewed;         278 AA.
AC   Q73AV4;
DT   15-MAR-2005, integrated into UniProtKB/Swiss-Prot.
DT   05-JUL-2004, sequence version 1.
DT   02-SEP-2026, entry version 110.
DE   RecName: Full=3-methyl-2-oxobutanoate hydroxymethyltransferase {ECO:0000255|HAMAP-Rule:MF_00156};
DE            EC=2.1.2.11 {ECO:0000255|HAMAP-Rule:MF_00156};
DE   AltName: Full=Ketopantoate hydroxymethyltransferase {ECO:0000255|HAMAP-Rule:MF_00156};
DE            Short=KPHMT {ECO:0000255|HAMAP-Rule:MF_00156};
GN   Name=panB {ECO:0000255|HAMAP-Rule:MF_00156};
GN   OrderedLocusNames=BCE_1668;
OS   Bacillus cereus (strain ATCC 10987 / NRS 248).
OC   Bacteria; Bacillati; Bacillota; Bacilli; Caryophanales; Bacillaceae;
OC   Bacillus; Bacillus cereus group.
OX   NCBI_TaxID=222523;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 10987 / NRS 248;
RX   PubMed=14960714; DOI=10.1093/nar/gkh258;
RA   Rasko D.A., Ravel J., Oekstad O.A., Helgason E., Cer R.Z., Jiang L.,
RA   Shores K.A., Fouts D.E., Tourasse N.J., Angiuoli S.V., Kolonay J.F.,
RA   Nelson W.C., Kolstoe A.-B., Fraser C.M., Read T.D.;
RT   "The genome sequence of Bacillus cereus ATCC 10987 reveals metabolic
RT   adaptations and a large plasmid related to Bacillus anthracis pXO1.";
RL   Nucleic Acids Res. 32:977-988(2004).
CC   -!- FUNCTION: Catalyzes the reversible reaction in which hydroxymethyl
CC       group from 5,10-methylenetetrahydrofolate is transferred onto alpha-
CC       ketoisovalerate to form ketopantoate. {ECO:0000255|HAMAP-
CC       Rule:MF_00156}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=(6R)-5,10-methylene-5,6,7,8-tetrahydrofolate + 3-methyl-2-
CC         oxobutanoate + H2O = 2-dehydropantoate + (6S)-5,6,7,8-
CC         tetrahydrofolate; Xref=Rhea:RHEA:11824, ChEBI:CHEBI:11561,
CC         ChEBI:CHEBI:11851, ChEBI:CHEBI:15377, ChEBI:CHEBI:15636,
CC         ChEBI:CHEBI:57453; EC=2.1.2.11; Evidence={ECO:0000255|HAMAP-
CC         Rule:MF_00156};
CC   -!- COFACTOR:
CC       Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Evidence={ECO:0000255|HAMAP-
CC         Rule:MF_00156};
CC       Note=Binds 1 Mg(2+) ion per subunit. {ECO:0000255|HAMAP-Rule:MF_00156};
CC   -!- PATHWAY: Cofactor biosynthesis; (R)-pantothenate biosynthesis; (R)-
CC       pantoate from 3-methyl-2-oxobutanoate: step 1/2. {ECO:0000255|HAMAP-
CC       Rule:MF_00156}.
CC   -!- SUBUNIT: Homodecamer; pentamer of dimers. {ECO:0000255|HAMAP-
CC       Rule:MF_00156}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000255|HAMAP-Rule:MF_00156}.
CC   -!- SIMILARITY: Belongs to the PanB family. {ECO:0000255|HAMAP-
CC       Rule:MF_00156}.
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DR   EMBL; AE017194; AAS40597.1; -; Genomic_DNA.
DR   AlphaFoldDB; Q73AV4; -.
DR   SMR; Q73AV4; -.
DR   KEGG; bca:BCE_1668; -.
DR   HOGENOM; CLU_036645_1_0_9; -.
DR   UniPathway; UPA00028; UER00003.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0003864; F:3-methyl-2-oxobutanoate hydroxymethyltransferase activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0000287; F:magnesium ion binding; IEA:TreeGrafter.
DR   GO; GO:0015940; P:pantothenate biosynthetic process; IEA:UniProtKB-UniRule.
DR   CDD; cd06557; KPHMT-like; 1.
DR   FunFam; 3.20.20.60:FF:000003; 3-methyl-2-oxobutanoate hydroxymethyltransferase; 1.
DR   Gene3D; 3.20.20.60; Phosphoenolpyruvate-binding domains; 1.
DR   HAMAP; MF_00156; PanB; 1.
DR   InterPro; IPR003700; Pantoate_hydroxy_MeTrfase.
DR   InterPro; IPR015813; Pyrv/PenolPyrv_kinase-like_dom.
DR   InterPro; IPR040442; Pyrv_kinase-like_dom_sf.
DR   NCBIfam; TIGR00222; panB; 1.
DR   NCBIfam; NF001452; PRK00311.1; 1.
DR   PANTHER; PTHR20881; 3-METHYL-2-OXOBUTANOATE HYDROXYMETHYLTRANSFERASE; 1.
DR   PANTHER; PTHR20881:SF0; 3-METHYL-2-OXOBUTANOATE HYDROXYMETHYLTRANSFERASE; 1.
DR   Pfam; PF02548; Pantoate_transf; 1.
DR   PIRSF; PIRSF000388; Pantoate_hydroxy_MeTrfase; 1.
DR   SUPFAM; SSF51621; Phosphoenolpyruvate/pyruvate domain; 1.
PE   3: Inferred from homology;
KW   Cytoplasm; Magnesium; Metal-binding; Pantothenate biosynthesis;
KW   Transferase.
FT   CHAIN           1..278
FT                   /note="3-methyl-2-oxobutanoate hydroxymethyltransferase"
FT                   /id="PRO_0000184809"
FT   ACT_SITE        181
FT                   /note="Proton acceptor"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         43..44
FT                   /ligand="3-methyl-2-oxobutanoate"
FT                   /ligand_id="ChEBI:CHEBI:11851"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         43
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         82
FT                   /ligand="3-methyl-2-oxobutanoate"
FT                   /ligand_id="ChEBI:CHEBI:11851"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         82
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         112
FT                   /ligand="3-methyl-2-oxobutanoate"
FT                   /ligand_id="ChEBI:CHEBI:11851"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         114
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
SQ   SEQUENCE   278 AA;  30457 MW;  658A3BAA42AA6FDC CRC64;
     MKTKTDFLKM KEQGEPITML TAYDYPSAKL AEEAEVDMIL VGDSLGMVVL GYDSTVPVTV
     EDMIHHTKAV RRGAKETFIV TDMPFMSYHV SPQDTMVNAR RIVQESGAHA LKVEGAGEVI
     STIHYLTSAG IPVVAHLGLT PQSVGVLGGY KVQGKDAESA KKLIEDAKRC EEAGAIALVL
     ECVPMQLAEF ISKQLTIPTI GIGAGQKVDG QVLVYHDLIS YGVNRVPKFV KQYTFVQEEI
     VRGISQYVTE VKTGQFPEEK HSFTMKEEEC LALYGGKQ
//