ID   PANB_RIPO1              Reviewed;         257 AA.
AC   B7JVF9;
DT   14-APR-2009, integrated into UniProtKB/Swiss-Prot.
DT   10-FEB-2009, sequence version 1.
DT   03-AUG-2022, entry version 70.
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=PCC8801_4370;
OS   Rippkaea orientalis (strain PCC 8801) (Cyanothece sp. (strain PCC 8801)).
OC   Bacteria; Cyanobacteria; Oscillatoriophycideae; Chroococcales;
OC   Aphanothecaceae; Rippkaea; Rippkaea orientalis.
OX   NCBI_TaxID=41431;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=PCC 8801;
RX   PubMed=21972240; DOI=10.1128/mbio.00214-11;
RA   Bandyopadhyay A., Elvitigala T., Welsh E., Stockel J., Liberton M., Min H.,
RA   Sherman L.A., Pakrasi H.B.;
RT   "Novel metabolic attributes of the genus Cyanothece, comprising a group of
RT   unicellular nitrogen-fixing Cyanobacteria.";
RL   MBio 2:E214-E214(2011).
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; CP001287; ACK68292.1; -; Genomic_DNA.
DR   RefSeq; WP_015785347.1; NC_011726.1.
DR   AlphaFoldDB; B7JVF9; -.
DR   SMR; B7JVF9; -.
DR   STRING; 41431.PCC8801_4370; -.
DR   EnsemblBacteria; ACK68292; ACK68292; PCC8801_4370.
DR   KEGG; cyp:PCC8801_4370; -.
DR   eggNOG; COG0413; Bacteria.
DR   HOGENOM; CLU_036645_1_0_3; -.
DR   OMA; VLVWTDM; -.
DR   OrthoDB; 916845at2; -.
DR   UniPathway; UPA00028; UER00003.
DR   Proteomes; UP000008204; 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..257
FT                   /note="3-methyl-2-oxobutanoate hydroxymethyltransferase"
FT                   /id="PRO_1000118120"
FT   ACT_SITE        182
FT                   /note="Proton acceptor"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         44..45
FT                   /ligand="3-methyl-2-oxobutanoate"
FT                   /ligand_id="ChEBI:CHEBI:11851"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         44
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         83
FT                   /ligand="3-methyl-2-oxobutanoate"
FT                   /ligand_id="ChEBI:CHEBI:11851"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         83
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         113
FT                   /ligand="3-methyl-2-oxobutanoate"
FT                   /ligand_id="ChEBI:CHEBI:11851"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
FT   BINDING         115
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00156"
SQ   SEQUENCE   257 AA;  27424 MW;  A69F35D7B7FC7699 CRC64;
     MAMTLPYLIQ AKQQGRPLVA LTAWDYAIAQ LLDGAGVDII LVGDSLAMVA LGHRTTLPIT
     LDEMIHHAKA VCRGVKQSLV VCDLPFLSYQ ESISQAIRSA GRVLKETGAQ GVKLEGGHAV
     AVETVQQLTS IGIPVMGHVG LTPQSVHRLG YRQQGQTEID AERIISEAIA LENAGVFALV
     LEHIPINLAA TITSKLSIPT IGIGAGPHCD GQVLVTADLL GLSKKQPPFA KSYLNLRGLI
     TEAVNEFSRE VREGEFP