ID   FABH_ROSCS              Reviewed;         330 AA.
AC   A7NK75;
DT   20-MAY-2008, integrated into UniProtKB/Swiss-Prot.
DT   02-OCT-2007, sequence version 1.
DT   25-MAY-2022, entry version 75.
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=Rcas_1803;
OS   Roseiflexus castenholzii (strain DSM 13941 / HLO8).
OC   Bacteria; Chloroflexi; Chloroflexia; Chloroflexales; Roseiflexineae;
OC   Roseiflexaceae; Roseiflexus.
OX   NCBI_TaxID=383372;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=DSM 13941 / HLO8;
RG   US DOE Joint Genome Institute;
RA   Copeland A., Lucas S., Lapidus A., Barry K., Glavina del Rio T., Dalin E.,
RA   Tice H., Pitluck S., Thompson L.S., Brettin T., Bruce D., Detter J.C.,
RA   Han C., Tapia R., Schmutz J., Larimer F., Land M., Hauser L., Kyrpides N.,
RA   Mikhailova N., Bryant D.A., Hanada S., Tsukatani Y., Richardson P.;
RT   "Complete sequence of Roseiflexus castenholzii DSM 13941.";
RL   Submitted (AUG-2007) 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; CP000804; ABU57895.1; -; Genomic_DNA.
DR   RefSeq; WP_012120320.1; NC_009767.1.
DR   AlphaFoldDB; A7NK75; -.
DR   SMR; A7NK75; -.
DR   STRING; 383372.Rcas_1803; -.
DR   EnsemblBacteria; ABU57895; ABU57895; Rcas_1803.
DR   KEGG; rca:Rcas_1803; -.
DR   eggNOG; COG0332; Bacteria.
DR   HOGENOM; CLU_039592_3_1_0; -.
DR   OMA; WGSEGDK; -.
DR   OrthoDB; 872193at2; -.
DR   UniPathway; UPA00094; -.
DR   Proteomes; UP000000263; 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..330
FT                   /note="3-oxoacyl-[acyl-carrier-protein] synthase 3"
FT                   /id="PRO_1000088320"
FT   REGION          255..259
FT                   /note="ACP-binding"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01815"
FT   ACT_SITE        114
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01815"
FT   ACT_SITE        254
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01815"
FT   ACT_SITE        284
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01815"
SQ   SEQUENCE   330 AA;  35008 MW;  C15D30A271C833B2 CRC64;
     MANFAAITGW GMAVPERVLT NADLERMVET SDEWIQTRTG IRERRIAGPG EHTSALSIAA
     GRAALARAGL DAAQIDTVIL ATCTPDRPFP ATACTVQAGV GARRAAAFDI VAACSGFVYG
     LQVATSMVRS GAARNVLFVA CDIFTHFINW NDRNTCVLFG DGAGAVVLQP SDEPAGLLSC
     VLGADGEQED LMAVDAGGTR LPATPELLEE GRQYVFMNGR EIFKHAVREM AASSFDALQA
     AGLSTDDVAL VIPHQANLRI IEATAKRLEV PLDRVFVNLD RYGNTSAASI PIALVEAVEQ
     QRLRKGDYAL LTSFGGGLTW ASAVIRWSAG