ID   PANB_PROMT              Reviewed;         272 AA.
AC   Q46JG1;
DT   24-JUL-2007, integrated into UniProtKB/Swiss-Prot.
DT   13-SEP-2005, sequence version 1.
DT   03-AUG-2022, entry version 90.
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=PMN2A_0876;
OS   Prochlorococcus marinus (strain NATL2A).
OC   Bacteria; Cyanobacteria; Synechococcales; Prochlorococcaceae;
OC   Prochlorococcus.
OX   NCBI_TaxID=59920;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=NATL2A;
RX   PubMed=18159947; DOI=10.1371/journal.pgen.0030231;
RA   Kettler G.C., Martiny A.C., Huang K., Zucker J., Coleman M.L., Rodrigue S.,
RA   Chen F., Lapidus A., Ferriera S., Johnson J., Steglich C., Church G.M.,
RA   Richardson P., Chisholm S.W.;
RT   "Patterns and implications of gene gain and loss in the evolution of
RT   Prochlorococcus.";
RL   PLoS Genet. 3:2515-2528(2007).
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}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   EMBL; CP000095; AAZ58367.1; -; Genomic_DNA.
DR   RefSeq; WP_011295224.1; NC_007335.2.
DR   AlphaFoldDB; Q46JG1; -.
DR   SMR; Q46JG1; -.
DR   STRING; 59920.PMN2A_0876; -.
DR   EnsemblBacteria; AAZ58367; AAZ58367; PMN2A_0876.
DR   KEGG; pmn:PMN2A_0876; -.
DR   HOGENOM; CLU_036645_1_0_3; -.
DR   OMA; VLVWTDM; -.
DR   OrthoDB; 916845at2; -.
DR   PhylomeDB; Q46JG1; -.
DR   UniPathway; UPA00028; UER00003.
DR   Proteomes; UP000002535; 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   Reference proteome; Transferase.
FT   CHAIN           1..272
FT                   /note="3-methyl-2-oxobutanoate hydroxymethyltransferase"
FT                   /id="PRO_0000297329"
FT   ACT_SITE        185
FT                   /note="Proton acceptor"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         42..43
FT                   /ligand="3-methyl-2-oxobutanoate"
FT                   /ligand_id="ChEBI:CHEBI:11851"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         42
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         86
FT                   /ligand="3-methyl-2-oxobutanoate"
FT                   /ligand_id="ChEBI:CHEBI:11851"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         86
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         116
FT                   /ligand="3-methyl-2-oxobutanoate"
FT                   /ligand_id="ChEBI:CHEBI:11851"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         118
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
SQ   SEQUENCE   272 AA;  29237 MW;  C2C19BA4A7F3383A CRC64;
     MQTTELVRFK KLGKQISVLT AWDAISSSIV EAAGADVVLV GDSLGMVVLG HSTTLPVTLD
     QMLHHTKAVC RGFCKPLSKQ PLVVCDLPFL SYQCGEDKAV EAAGTLLKNS TASAVKLEGA
     EPETLLVIKR LIRMGIPVMG HLGLTPQSVH QLGYKSQARD KDSQEKIFKD SKMLQESGCF
     AIVLEHIPGE IASRLKKHID IPVIGIGAGN DCDGQVRVTA DILGLSIAQP PFAKPLLAGR
     ELCINALKEW INSTDLDQVN PTTKTSESKS DC