ID   FABH_SPIOL              Reviewed;         405 AA.
AC   Q07510;
DT   01-FEB-1996, integrated into UniProtKB/Swiss-Prot.
DT   01-FEB-1996, sequence version 1.
DT   25-MAY-2022, entry version 98.
DE   RecName: Full=3-oxoacyl-[acyl-carrier-protein] synthase III, chloroplastic;
DE            EC=2.3.1.180;
DE   AltName: Full=Beta-ketoacyl-ACP synthase III;
DE            Short=KAS III;
DE   Flags: Precursor;
OS   Spinacia oleracea (Spinach).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   Caryophyllales; Chenopodiaceae; Chenopodioideae; Anserineae; Spinacia.
OX   NCBI_TaxID=3562;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], AND PARTIAL PROTEIN SEQUENCE.
RC   TISSUE=Leaf, and Root;
RX   PubMed=8290632; DOI=10.1104/pp.103.4.1361;
RA   Tai H., Jaworski J.G.;
RT   "3-ketoacyl-acyl carrier protein synthase III from spinach (Spinacia
RT   oleracea) is not similar to other condensing enzymes of fatty acid
RT   synthase.";
RL   Plant Physiol. 103:1361-1367(1993).
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       KAS III catalyzes the first condensation reaction which initiates fatty
CC       acid synthesis and may therefore play a role in governing the total
CC       rate of fatty acid production. Possesses both acetoacetyl-ACP synthase
CC       and acetyl transacylase activities (By similarity). {ECO:0000250}.
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;
CC   -!- ACTIVITY REGULATION: No inhibition by the antibiotic cerulenin.
CC   -!- PATHWAY: Lipid metabolism; fatty acid biosynthesis.
CC   -!- SUBCELLULAR LOCATION: Plastid, chloroplast.
CC   -!- TISSUE SPECIFICITY: Expressed in both leaf and root.
CC   -!- SIMILARITY: Belongs to the thiolase-like superfamily. FabH family.
CC       {ECO:0000305}.
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; Z22771; CAA80452.1; -; mRNA.
DR   PIR; JQ2386; JQ2386.
DR   AlphaFoldDB; Q07510; -.
DR   SMR; Q07510; -.
DR   OrthoDB; 689748at2759; -.
DR   BRENDA; 2.3.1.180; 5812.
DR   UniPathway; UPA00094; -.
DR   GO; GO:0009507; C:chloroplast; 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-EC.
DR   GO; GO:0006633; P:fatty acid biosynthetic process; IEA:UniProtKB-UniPathway.
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   1: Evidence at protein level;
KW   Chloroplast; Direct protein sequencing; Fatty acid biosynthesis;
KW   Fatty acid metabolism; Lipid biosynthesis; Lipid metabolism; Plastid;
KW   Transferase; Transit peptide.
FT   TRANSIT         1..?
FT                   /note="Chloroplast"
FT                   /evidence="ECO:0000255"
FT   CHAIN           ?..405
FT                   /note="3-oxoacyl-[acyl-carrier-protein] synthase III,
FT                   chloroplastic"
FT                   /id="PRO_0000008735"
FT   ACT_SITE        181
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        331
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        361
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   405 AA;  42534 MW;  DE3B5CE194E1CEB2 CRC64;
     MATSYGFFSP SVPSSLNNKI SPSLGINGSG FCSHLGISKR VFCSSIEASE KHAAAGVSSS
     ESRVSRLVNR GCKLVGCGSA VPKLQISNDD LSKFVETSDE WIATRTGIRQ RHVLSGKDSL
     VDLAAEAARN ALQMANVNPD DIDLILMCTS TPEDLFGSAP QVQRALGCSR TPLSYDITAA
     CSGFMLGLVS AACHVRGGGF KNVLVIGADA LSRFVDWTDR GTCILFGDAA GAVVVQACDS
     EEDGMFAFDL HSDGGGGRHL NASLLNDETD AAIGNNGAVT GFPPKRPSYS CINMNGKEVF
     RFAVRCVPQS IEAALQKAGL TSSNIDWLLL HQANQRIIDA VATRLEVPSE RVLSNLANYG
     NTSAASIPLA LDEAVRSGKV KPGNIIATSG FGAGLTWGSS IIRWG