ID   PANB_CHLCH              Reviewed;         277 AA.
AC   Q3AS53;
DT   24-JUL-2007, integrated into UniProtKB/Swiss-Prot.
DT   22-NOV-2005, sequence version 1.
DT   03-AUG-2022, entry version 94.
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}; OrderedLocusNames=Cag_0907;
OS   Chlorobium chlorochromatii (strain CaD3).
OC   Bacteria; Chlorobi; Chlorobia; Chlorobiales; Chlorobiaceae;
OC   Chlorobium/Pelodictyon group; Chlorobium.
OX   NCBI_TaxID=340177;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=CaD3;
RG   US DOE Joint Genome Institute;
RA   Copeland A., Lucas S., Lapidus A., Barry K., Detter J.C., Glavina T.,
RA   Hammon N., Israni S., Pitluck S., Bryant D., Schmutz J., Larimer F.,
RA   Land M., Kyrpides N., Ivanova N., Richardson P.;
RT   "Complete sequence of Chlorobium chlorochromatii CaD3.";
RL   Submitted (AUG-2005) to the EMBL/GenBank/DDBJ databases.
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 = (6S)-5,6,7,8-tetrahydrofolate + 2-
CC         dehydropantoate; 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;
CC         Evidence={ECO:0000255|HAMAP-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; CP000108; ABB28172.1; -; Genomic_DNA.
DR   RefSeq; WP_011361940.1; NC_007514.1.
DR   AlphaFoldDB; Q3AS53; -.
DR   SMR; Q3AS53; -.
DR   STRING; 340177.Cag_0907; -.
DR   EnsemblBacteria; ABB28172; ABB28172; Cag_0907.
DR   KEGG; cch:Cag_0907; -.
DR   eggNOG; COG0413; Bacteria.
DR   HOGENOM; CLU_036645_1_0_10; -.
DR   OMA; VLVWTDM; -.
DR   OrthoDB; 916845at2; -.
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:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0015940; P:pantothenate biosynthetic process; IEA:UniProtKB-UniRule.
DR   CDD; cd06557; KPHMT-like; 1.
DR   Gene3D; 3.20.20.60; -; 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   PANTHER; PTHR20881; PTHR20881; 1.
DR   Pfam; PF02548; Pantoate_transf; 1.
DR   PIRSF; PIRSF000388; Pantoate_hydroxy_MeTrfase; 1.
DR   SUPFAM; SSF51621; SSF51621; 1.
DR   TIGRFAMs; TIGR00222; panB; 1.
PE   3: Inferred from homology;
KW   Cytoplasm; Magnesium; Metal-binding; Pantothenate biosynthesis;
KW   Transferase.
FT   CHAIN           1..277
FT                   /note="3-methyl-2-oxobutanoate hydroxymethyltransferase"
FT                   /id="PRO_0000297243"
FT   ACT_SITE        195
FT                   /note="Proton acceptor"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         53..54
FT                   /ligand="3-methyl-2-oxobutanoate"
FT                   /ligand_id="ChEBI:CHEBI:11851"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         53
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         96
FT                   /ligand="3-methyl-2-oxobutanoate"
FT                   /ligand_id="ChEBI:CHEBI:11851"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         96
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         126
FT                   /ligand="3-methyl-2-oxobutanoate"
FT                   /ligand_id="ChEBI:CHEBI:11851"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         128
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
SQ   SEQUENCE   277 AA;  30651 MW;  57909A59912645A3 CRC64;
     MPHRDQPKTA HVTTRRLLDM KQQGEKISML TAYDYTMARI LDRAGVDVLL VGDSASNVFS
     GHSTTLPITI EEMIYHAKAV VRGVHDETGR AMVVIDMPFM SYQLSSEEAL RNAGKIMKEH
     ECDAVKMEGG HVIVESVKRI TDVGIPVMGH LGLMPQSIYK YGSYRVRAQE EQEAEQLLRD
     AELLEKAGAF AIVLEKIPSA LAAQVTASLT IPTIGIGAGV ACDGQVLVIN DILGLNREFH
     PRFVRQYVDL NSMIEQVARQ YVTDVRGCDF PSSNESY