ID   FABH_RICBR              Reviewed;         317 AA.
AC   Q1RKA5;
DT   23-JAN-2007, integrated into UniProtKB/Swiss-Prot.
DT   16-MAY-2006, sequence version 1.
DT   03-AUG-2022, entry version 98.
DE   RecName: Full=3-oxoacyl-[acyl-carrier-protein] synthase 3 {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 III {ECO:0000255|HAMAP-Rule:MF_01815};
DE   AltName: Full=Beta-ketoacyl-ACP synthase III {ECO:0000255|HAMAP-Rule:MF_01815};
DE            Short=KAS III {ECO:0000255|HAMAP-Rule:MF_01815};
GN   Name=fabH {ECO:0000255|HAMAP-Rule:MF_01815}; OrderedLocusNames=RBE_0128;
OS   Rickettsia bellii (strain RML369-C).
OC   Bacteria; Proteobacteria; Alphaproteobacteria; Rickettsiales;
OC   Rickettsiaceae; Rickettsieae; Rickettsia; belli group.
OX   NCBI_TaxID=336407;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=RML369-C;
RX   PubMed=16703114; DOI=10.1371/journal.pgen.0020076;
RA   Ogata H., La Scola B., Audic S., Renesto P., Blanc G., Robert C.,
RA   Fournier P.-E., Claverie J.-M., Raoult D.;
RT   "Genome sequence of Rickettsia bellii illuminates the role of amoebae in
RT   gene exchanges between intracellular pathogens.";
RL   PLoS Genet. 2:733-744(2006).
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=acetyl-CoA + H(+) + malonyl-[ACP] = 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; CP000087; ABE04209.1; -; Genomic_DNA.
DR   RefSeq; WP_011476824.1; NC_007940.1.
DR   AlphaFoldDB; Q1RKA5; -.
DR   SMR; Q1RKA5; -.
DR   STRING; 336407.RBE_0128; -.
DR   EnsemblBacteria; ABE04209; ABE04209; RBE_0128.
DR   KEGG; rbe:RBE_0128; -.
DR   eggNOG; COG0332; Bacteria.
DR   HOGENOM; CLU_039592_3_1_5; -.
DR   OMA; QFVFKNA; -.
DR   OrthoDB; 872193at2; -.
DR   UniPathway; UPA00094; -.
DR   Proteomes; UP000001951; Chromosome.
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   Gene3D; 3.40.47.10; -; 1.
DR   HAMAP; MF_01815; FabH; 1.
DR   InterPro; IPR013751; ACP_syn_III.
DR   InterPro; IPR013747; ACP_syn_III_C.
DR   InterPro; IPR004655; FabH_synth.
DR   InterPro; IPR016039; Thiolase-like.
DR   Pfam; PF08545; ACP_syn_III; 1.
DR   Pfam; PF08541; ACP_syn_III_C; 1.
DR   SUPFAM; SSF53901; SSF53901; 1.
DR   TIGRFAMs; TIGR00747; fabH; 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..317
FT                   /note="3-oxoacyl-[acyl-carrier-protein] synthase 3"
FT                   /id="PRO_0000272375"
FT   REGION          245..249
FT                   /note="ACP-binding"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01815"
FT   ACT_SITE        112
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01815"
FT   ACT_SITE        244
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01815"
FT   ACT_SITE        274
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01815"
SQ   SEQUENCE   317 AA;  34293 MW;  FC8200C241E3D28B CRC64;
     MTCKIIGCGG YLPPKVVSND ELAKFVDTND EWIRTRTGIS QRHIAGDTEY TSHIALKAAE
     KAIADADISV NEIDLIITCT TTPDNSFPSV ATKLQGYLGL NNVPSFDLQA VCAGFVYGVQ
     VANSLISSGK YKTILLIGAE KMTSLLDWED RATCVLFGDG AGSVILQRSD DNSGIIDSNI
     FSSGADYEIL YTNGGVSMNG SSGKIIMQGQ KLFRLAVEKM HQSIEELLRN NNFTVNDIDY
     FIPHQANVRI INKLAELLNV EDHKVVKTVE KHANCSSASI PLALSTLKAS GKIKKGDIIL
     FSAIGAGLTW GSALLRW