ID   FABH_HELPS              Reviewed;         331 AA.
AC   B2US32;
DT   28-JUL-2009, integrated into UniProtKB/Swiss-Prot.
DT   01-JUL-2008, sequence version 1.
DT   04-NOV-2026, entry version 85.
DE   RecName: Full=Beta-ketoacyl-[acyl-carrier-protein] synthase III {ECO:0000255|HAMAP-Rule:MF_01815};
DE            Short=Beta-ketoacyl-ACP synthase III {ECO:0000255|HAMAP-Rule:MF_01815};
DE            Short=KAS III {ECO:0000255|HAMAP-Rule:MF_01815};
DE            EC=2.3.1.180 {ECO:0000255|HAMAP-Rule:MF_01815};
DE   AltName: Full=3-oxoacyl-[acyl-carrier-protein] synthase 3 {ECO:0000255|HAMAP-Rule:MF_01815};
DE   AltName: Full=3-oxoacyl-[acyl-carrier-protein] synthase III {ECO:0000255|HAMAP-Rule:MF_01815};
GN   Name=fabH {ECO:0000255|HAMAP-Rule:MF_01815};
GN   OrderedLocusNames=HPSH_01035;
OS   Helicobacter pylori (strain Shi470).
OC   Bacteria; Pseudomonadati; Campylobacterota; Epsilonproteobacteria;
OC   Campylobacterales; Helicobacteraceae; Helicobacter.
OX   NCBI_TaxID=512562;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=Shi470;
RA   Kersulyte D., Kalia A., Gilman R.H., Berg D.E.;
RT   "Genome sequence of Helicobacter pylori from the remote Amazon: traces of
RT   Asian ancestry of the first Americans.";
RL   Submitted (MAY-2008) to the EMBL/GenBank/DDBJ databases.
CC   -!- FUNCTION: Catalyzes the condensation reaction of fatty acid synthesis
CC       by the addition to an acyl acceptor of two carbons from malonyl-ACP.
CC       Catalyzes the first condensation reaction which initiates fatty acid
CC       synthesis and may therefore play a role in governing the total rate of
CC       fatty acid production. Possesses both acetoacetyl-ACP synthase and
CC       acetyl transacylase activities. Its substrate specificity determines
CC       the biosynthesis of branched-chain and/or straight-chain of fatty
CC       acids. {ECO:0000255|HAMAP-Rule:MF_01815}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=malonyl-[ACP] + acetyl-CoA + H(+) = 3-oxobutanoyl-[ACP] + CO2
CC         + CoA; Xref=Rhea:RHEA:12080, Rhea:RHEA-COMP:9623, Rhea:RHEA-
CC         COMP:9625, ChEBI:CHEBI:15378, ChEBI:CHEBI:16526, ChEBI:CHEBI:57287,
CC         ChEBI:CHEBI:57288, ChEBI:CHEBI:78449, ChEBI:CHEBI:78450;
CC         EC=2.3.1.180; Evidence={ECO:0000255|HAMAP-Rule:MF_01815};
CC   -!- PATHWAY: Lipid metabolism; fatty acid biosynthesis. {ECO:0000255|HAMAP-
CC       Rule:MF_01815}.
CC   -!- SUBUNIT: Homodimer. {ECO:0000255|HAMAP-Rule:MF_01815}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000255|HAMAP-Rule:MF_01815}.
CC   -!- DOMAIN: The last Arg residue of the ACP-binding site is essential for
CC       the weak association between ACP/AcpP and FabH. {ECO:0000255|HAMAP-
CC       Rule:MF_01815}.
CC   -!- SIMILARITY: Belongs to the thiolase-like superfamily. FabH family.
CC       {ECO:0000255|HAMAP-Rule:MF_01815}.
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DR   EMBL; CP001072; ACD47664.1; -; Genomic_DNA.
DR   RefSeq; WP_000397777.1; NC_010698.2.
DR   AlphaFoldDB; B2US32; -.
DR   SMR; B2US32; -.
DR   KEGG; hps:HPSH_01035; -.
DR   HOGENOM; CLU_039592_4_1_7; -.
DR   OMA; AACCGYI; -.
DR   UniPathway; UPA00094; -.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0004315; F:3-oxoacyl-[acyl-carrier-protein] synthase activity; IEA:InterPro.
DR   GO; GO:0033818; F:beta-ketoacyl-acyl-carrier-protein synthase III activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0006633; P:fatty acid biosynthetic process; IEA:UniProtKB-UniRule.
DR   GO; GO:0044550; P:secondary metabolite biosynthetic process; IEA:TreeGrafter.
DR   CDD; cd00830; KAS_III; 1.
DR   FunFam; 3.40.47.10:FF:000004; 3-oxoacyl-[acyl-carrier-protein] synthase 3; 1.
DR   Gene3D; 3.40.47.10; -; 1.
DR   HAMAP; MF_01815; FabH; 1.
DR   InterPro; IPR013747; ACP_syn_III_C.
DR   InterPro; IPR013751; ACP_syn_III_N.
DR   InterPro; IPR004655; FabH.
DR   InterPro; IPR016039; Thiolase-like.
DR   NCBIfam; TIGR00747; fabH; 1.
DR   NCBIfam; NF006829; PRK09352.1; 1.
DR   PANTHER; PTHR34069; 3-OXOACYL-[ACYL-CARRIER-PROTEIN] SYNTHASE 3; 1.
DR   PANTHER; PTHR34069:SF2; BETA-KETOACYL-[ACYL-CARRIER-PROTEIN] SYNTHASE III; 1.
DR   Pfam; PF08545; ACP_syn_III; 1.
DR   Pfam; PF08541; ACP_syn_III_C; 1.
DR   SUPFAM; SSF53901; Thiolase-like; 1.
PE   3: Inferred from homology;
KW   Acyltransferase; Cytoplasm; Fatty acid biosynthesis; Fatty acid metabolism;
KW   Lipid biosynthesis; Lipid metabolism; Multifunctional enzyme; Transferase.
FT   CHAIN           1..331
FT                   /note="Beta-ketoacyl-[acyl-carrier-protein] synthase III"
FT                   /id="PRO_1000187870"
FT   REGION          256..260
FT                   /note="ACP-binding"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01815"
FT   ACT_SITE        115
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01815"
FT   ACT_SITE        255
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01815"
FT   ACT_SITE        285
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01815"
SQ   SEQUENCE   331 AA;  36494 MW;  C0DAE6ABBCD1A403 CRC64;
     MEFYASLKSI AMHVPSERVK NAEFQQFLDT SDEWIEKRTG IKERRFANDE EKSSDLGVIA
     AKQAIERAHL TPKDIDLVVV ATLSPDFLAM PSTACVLSAK LGIENKPAFD ISAACTGFIY
     LLSVAKAYVE SGMCENVLIV GAEKTSSVLD FKDRGTCILF GDGAGACVIG RTKRLKESVL
     DVQISANGNF SNYLYTPRTL KPTPFNAKEE ASEPFLRMKG NEVFKLAVKT LLKDVEMILE
     KNALKPEDVR LFIPHQANFR IIQAVREHLD FKDEQVVLTV HKYGNTSAAS IPMAMCEAYE
     EGRLKKGDLM LLDAFGGGLT WGSALVYFGG S
//