ID PANB_BACFN Reviewed; 273 AA. AC Q5LD96; DT 24-JUL-2007, integrated into UniProtKB/Swiss-Prot. DT 21-JUN-2005, sequence version 1. DT 10-JUN-2026, entry version 106. 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=BF2220; OS Bacteroides fragilis (strain ATCC 25285 / DSM 2151 / CCUG 4856 / JCM 11019 OS / LMG 10263 / NCTC 9343 / Onslow / VPI 2553 / EN-2). OC Bacteria; Pseudomonadati; Bacteroidota; Bacteroidia; Bacteroidales; OC Bacteroidaceae; Bacteroides. OX NCBI_TaxID=272559; RN [1] RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. RC STRAIN=ATCC 25285 / DSM 2151 / CCUG 4856 / JCM 11019 / LMG 10263 / RC NCTC 9343 / Onslow / VPI 2553 / EN-2; RX PubMed=15746427; DOI=10.1126/science.1107008; RA Cerdeno-Tarraga A.-M., Patrick S., Crossman L.C., Blakely G., Abratt V., RA Lennard N., Poxton I., Duerden B., Harris B., Quail M.A., Barron A., RA Clark L., Corton C., Doggett J., Holden M.T.G., Larke N., Line A., Lord A., RA Norbertczak H., Ormond D., Price C., Rabbinowitsch E., Woodward J., RA Barrell B.G., Parkhill J.; RT "Extensive DNA inversions in the B. fragilis genome control variable gene RT expression."; RL Science 307:1463-1465(2005). 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}. 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; CR626927; CAH07914.1; -; Genomic_DNA. DR RefSeq; WP_005787461.1; NC_003228.3. DR AlphaFoldDB; Q5LD96; -. DR SMR; Q5LD96; -. DR GeneID; 60367359; -. DR KEGG; bfs:BF9343_2133; -. DR eggNOG; COG0413; Bacteria. DR HOGENOM; CLU_036645_1_0_10; -. DR UniPathway; UPA00028; UER00003. DR Proteomes; UP000006731; 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: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:000017; 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 Reference proteome; Transferase. FT CHAIN 1..273 FT /note="3-methyl-2-oxobutanoate hydroxymethyltransferase" FT /id="PRO_0000297222" FT ACT_SITE 191 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 92 FT /ligand="3-methyl-2-oxobutanoate" FT /ligand_id="ChEBI:CHEBI:11851" FT /evidence="ECO:0000255|HAMAP-Rule:MF_00156" FT BINDING 92 FT /ligand="Mg(2+)" FT /ligand_id="ChEBI:CHEBI:18420" FT /evidence="ECO:0000255|HAMAP-Rule:MF_00156" FT BINDING 122 FT /ligand="3-methyl-2-oxobutanoate" FT /ligand_id="ChEBI:CHEBI:11851" FT /evidence="ECO:0000255|HAMAP-Rule:MF_00156" FT BINDING 124 FT /ligand="Mg(2+)" FT /ligand_id="ChEBI:CHEBI:18420" FT /evidence="ECO:0000255|HAMAP-Rule:MF_00156" SQ SEQUENCE 273 AA; 29807 MW; F7EABB8AF3842932 CRC64; MAGYISDDTR KVTTHRLIEM KQRGEKISML TSYDYTMAQI VDGAGIDVIL VGDSASNVMA GNVTTLPITL DQMIYHGKSV VRGVKRAMVV VDMPFGSYQG NEMEGLASAI RIMKESHADA LKLEGGEEII DTVKRILSAG IPVMGHLGLM PQSINKYGTY TVRAKDDAEA EKLIRDAHLL EEAGCFGLVL EKIPAALASR VASELTIPVI GIGAGGDVDG QVLVIQDMLG MNNGFRPRFL RRYADLYTVM TDAISHYVSD VKNCDFPNEK EQY //