ID   FABH_CHLCH              Reviewed;         329 AA.
AC   Q3AQ09;
DT   15-JAN-2008, integrated into UniProtKB/Swiss-Prot.
DT   22-NOV-2005, sequence version 1.
DT   25-MAY-2022, entry version 93.
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=Cag_1664;
OS   Chlorobium chlorochromatii (strain CaD3).
OC   Bacteria; Chlorobi; Chlorobia; Chlorobiales; Chlorobiaceae;
OC   Chlorobium/Pelodictyon group; Chlorobium.
OX   NCBI_TaxID=340177;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=CaD3;
RG   US DOE Joint Genome Institute;
RA   Copeland A., Lucas S., Lapidus A., Barry K., Detter J.C., Glavina T.,
RA   Hammon N., Israni S., Pitluck S., Bryant D., Schmutz J., Larimer F.,
RA   Land M., Kyrpides N., Ivanova N., Richardson P.;
RT   "Complete sequence of Chlorobium chlorochromatii CaD3.";
RL   Submitted (AUG-2005) 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=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; CP000108; ABB28916.1; -; Genomic_DNA.
DR   RefSeq; WP_011362678.1; NC_007514.1.
DR   AlphaFoldDB; Q3AQ09; -.
DR   SMR; Q3AQ09; -.
DR   STRING; 340177.Cag_1664; -.
DR   EnsemblBacteria; ABB28916; ABB28916; Cag_1664.
DR   KEGG; cch:Cag_1664; -.
DR   eggNOG; COG0332; Bacteria.
DR   HOGENOM; CLU_039592_3_1_10; -.
DR   OMA; WGSEGDK; -.
DR   OrthoDB; 872193at2; -.
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   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..329
FT                   /note="3-oxoacyl-[acyl-carrier-protein] synthase 3"
FT                   /id="PRO_1000056339"
FT   REGION          256..260
FT                   /note="ACP-binding"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01815"
FT   ACT_SITE        113
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   329 AA;  35744 MW;  35462C0B369355DF CRC64;
     MKAAITATAN YLPPDILSNH DLELMLDTND EWIRSRTGIG ERRILKDPTK ATSYMCGEVA
     RQLLEKRQLA ATDIELIIVA TITPDMPFPA TACLVQDLIG AKNAWAFDLN AACSGFLYAL
     NTAIRFVESG AHKKVMVIGA DKMSSIIDYT DRATAILFGD GAGGVLVEPA ADDSCGVLDV
     RLYSDGTNGR ERLLMTGGGS RYPASHETVD KKMHYIYQDG RQVFKAAVTA MADVATEIMQ
     RNNLTADDVA YLVPHQANQR IIDAIAERMG VDRAKVVSNV GYYGNTTAGT IPICLAELDA
     NNKLKHGDNL VLVSFGAGYT WGGIYVKWQ