ID   PANB_BUCA5              Reviewed;         263 AA.
AC   B8D8Z6;
DT   28-JUL-2009, integrated into UniProtKB/Swiss-Prot.
DT   03-MAR-2009, sequence version 1.
DT   03-AUG-2022, entry version 67.
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=BUAP5A_194;
OS   Buchnera aphidicola subsp. Acyrthosiphon pisum (strain 5A).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC   Erwiniaceae; Buchnera.
OX   NCBI_TaxID=563178;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=5A;
RX   PubMed=19150844; DOI=10.1126/science.1167140;
RA   Moran N.A., McLaughlin H.J., Sorek R.;
RT   "The dynamics and time scale of ongoing genomic erosion in symbiotic
RT   bacteria.";
RL   Science 323:379-382(2009).
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; CP001161; ACL30567.1; -; Genomic_DNA.
DR   RefSeq; WP_009874154.1; NC_011833.1.
DR   AlphaFoldDB; B8D8Z6; -.
DR   SMR; B8D8Z6; -.
DR   KEGG; bap:BUAP5A_194; -.
DR   HOGENOM; CLU_036645_1_0_6; -.
DR   OMA; VLVWTDM; -.
DR   OrthoDB; 916845at2; -.
DR   UniPathway; UPA00028; UER00003.
DR   Proteomes; UP000006904; Chromosome.
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..263
FT                   /note="3-methyl-2-oxobutanoate hydroxymethyltransferase"
FT                   /id="PRO_1000123372"
FT   ACT_SITE        181
FT                   /note="Proton acceptor"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         45..46
FT                   /ligand="3-methyl-2-oxobutanoate"
FT                   /ligand_id="ChEBI:CHEBI:11851"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         45
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         84
FT                   /ligand="3-methyl-2-oxobutanoate"
FT                   /ligand_id="ChEBI:CHEBI:11851"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         84
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   263 AA;  29346 MW;  572CC9AF87E84450 CRC64;
     MESITISQLK NWKRNKKKIA AITAYDFSFS RLFSNCGIPV ILIGDSLGMT IQGHTSTLPV
     KIEDIAYHTK AVRKGAPNTF LISDLPFMSY YDTKQALKNT AKIIRSGANM IKMEGGKWLI
     EIIRELSNRL ILICGHIGLI PQSFHYLGGY KVQGRKENDA NKLIDEALLL EEAGINMLIL
     ECIPEKLAKK ITESLSIPVI GIGSGKNTDG QILVMHDLLG ITEGKTPSFT KNFLSESDSI
     QKAIQKYIYE VEHSIYPSKK HSF