ID   FABB_ECOL6              Reviewed;         406 AA.
AC   P0A954; P14926; Q9R828; Q9R829; Q9R830;
DT   19-JUL-2005, integrated into UniProtKB/Swiss-Prot.
DT   19-JUL-2005, sequence version 1.
DT   27-MAR-2024, entry version 99.
DE   RecName: Full=3-oxoacyl-[acyl-carrier-protein] synthase 1 {ECO:0000250|UniProtKB:P0A953};
DE            EC=2.3.1.41 {ECO:0000250|UniProtKB:P0A953};
DE   AltName: Full=3-oxoacyl-[acyl-carrier-protein] synthase I {ECO:0000250|UniProtKB:P0A953};
DE   AltName: Full=Beta-ketoacyl-ACP synthase I {ECO:0000250|UniProtKB:P0A953};
DE            Short=KAS I {ECO:0000250|UniProtKB:P0A953};
GN   Name=fabB; OrderedLocusNames=c2869;
OS   Escherichia coli O6:H1 (strain CFT073 / ATCC 700928 / UPEC).
OC   Bacteria; Pseudomonadota; Gammaproteobacteria; Enterobacterales;
OC   Enterobacteriaceae; Escherichia.
OX   NCBI_TaxID=199310;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=CFT073 / ATCC 700928 / UPEC;
RX   PubMed=12471157; DOI=10.1073/pnas.252529799;
RA   Welch R.A., Burland V., Plunkett G. III, Redford P., Roesch P., Rasko D.,
RA   Buckles E.L., Liou S.-R., Boutin A., Hackett J., Stroud D., Mayhew G.F.,
RA   Rose D.J., Zhou S., Schwartz D.C., Perna N.T., Mobley H.L.T.,
RA   Donnenberg M.S., Blattner F.R.;
RT   "Extensive mosaic structure revealed by the complete genome sequence of
RT   uropathogenic Escherichia coli.";
RL   Proc. Natl. Acad. Sci. U.S.A. 99:17020-17024(2002).
CC   -!- FUNCTION: Involved in the type II fatty acid elongation cycle.
CC       Catalyzes the elongation of a wide range of acyl-ACP by the addition of
CC       two carbons from malonyl-ACP to an acyl acceptor. Can also use
CC       unsaturated fatty acids. Catalyzes a key reaction in unsaturated fatty
CC       acid (UFA) synthesis, the elongation of the cis-3-decenoyl-ACP produced
CC       by FabA. {ECO:0000250|UniProtKB:P0A953}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=a fatty acyl-[ACP] + H(+) + malonyl-[ACP] = a 3-oxoacyl-[ACP]
CC         + CO2 + holo-[ACP]; Xref=Rhea:RHEA:22836, Rhea:RHEA-COMP:9623,
CC         Rhea:RHEA-COMP:9685, Rhea:RHEA-COMP:9916, Rhea:RHEA-COMP:14125,
CC         ChEBI:CHEBI:15378, ChEBI:CHEBI:16526, ChEBI:CHEBI:64479,
CC         ChEBI:CHEBI:78449, ChEBI:CHEBI:78776, ChEBI:CHEBI:138651;
CC         EC=2.3.1.41; Evidence={ECO:0000250|UniProtKB:P0A953};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:22837;
CC         Evidence={ECO:0000250|UniProtKB:P0A953};
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=(3Z)-decenoyl-[ACP] + H(+) + malonyl-[ACP] = 3-oxo-(5Z)-
CC         dodecenoyl-[ACP] + CO2 + holo-[ACP]; Xref=Rhea:RHEA:54940, Rhea:RHEA-
CC         COMP:9623, Rhea:RHEA-COMP:9685, Rhea:RHEA-COMP:9927, Rhea:RHEA-
CC         COMP:14042, ChEBI:CHEBI:15378, ChEBI:CHEBI:16526, ChEBI:CHEBI:64479,
CC         ChEBI:CHEBI:78449, ChEBI:CHEBI:78798, ChEBI:CHEBI:138410;
CC         Evidence={ECO:0000250|UniProtKB:P0A953};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:54941;
CC         Evidence={ECO:0000250|UniProtKB:P0A953};
CC   -!- PATHWAY: Lipid metabolism; fatty acid biosynthesis.
CC       {ECO:0000250|UniProtKB:P0A953}.
CC   -!- SUBUNIT: Homodimer. {ECO:0000250|UniProtKB:P0A953}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000250|UniProtKB:P0A953}.
CC   -!- SIMILARITY: Belongs to the thiolase-like superfamily. Beta-ketoacyl-ACP
CC       synthases family. {ECO:0000305}.
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DR   EMBL; AE014075; AAN81319.1; -; Genomic_DNA.
DR   RefSeq; WP_000817178.1; NZ_CP051263.1.
DR   AlphaFoldDB; P0A954; -.
DR   SMR; P0A954; -.
DR   STRING; 199310.c2869; -.
DR   GeneID; 75202594; -.
DR   KEGG; ecc:c2869; -.
DR   eggNOG; COG0304; Bacteria.
DR   HOGENOM; CLU_000022_69_2_6; -.
DR   BioCyc; ECOL199310:C2869-MONOMER; -.
DR   UniPathway; UPA00094; -.
DR   Proteomes; UP000001410; Chromosome.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0004315; F:3-oxoacyl-[acyl-carrier-protein] synthase activity; IEA:UniProtKB-EC.
DR   GO; GO:0006633; P:fatty acid biosynthetic process; IEA:UniProtKB-UniPathway.
DR   CDD; cd00834; KAS_I_II; 1.
DR   Gene3D; 3.40.47.10; -; 2.
DR   InterPro; IPR000794; Beta-ketoacyl_synthase.
DR   InterPro; IPR018201; Ketoacyl_synth_AS.
DR   InterPro; IPR014031; Ketoacyl_synth_C.
DR   InterPro; IPR014030; Ketoacyl_synth_N.
DR   InterPro; IPR020841; PKS_Beta-ketoAc_synthase_dom.
DR   InterPro; IPR016039; Thiolase-like.
DR   PANTHER; PTHR11712:SF306; 3-OXOACYL-[ACYL-CARRIER-PROTEIN] SYNTHASE 1; 1.
DR   PANTHER; PTHR11712; POLYKETIDE SYNTHASE-RELATED; 1.
DR   Pfam; PF00109; ketoacyl-synt; 1.
DR   Pfam; PF02801; Ketoacyl-synt_C; 1.
DR   SMART; SM00825; PKS_KS; 1.
DR   SUPFAM; SSF53901; Thiolase-like; 2.
DR   PROSITE; PS00606; KS3_1; 1.
DR   PROSITE; PS52004; KS3_2; 1.
PE   3: Inferred from homology;
KW   Acyltransferase; Cytoplasm; Fatty acid biosynthesis; Fatty acid metabolism;
KW   Lipid biosynthesis; Lipid metabolism; Reference proteome; Transferase.
FT   CHAIN           1..406
FT                   /note="3-oxoacyl-[acyl-carrier-protein] synthase 1"
FT                   /id="PRO_0000180312"
FT   DOMAIN          1..403
FT                   /note="Ketosynthase family 3 (KS3)"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01348"
FT   ACT_SITE        163
FT                   /note="For beta-ketoacyl synthase activity"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01348"
FT   ACT_SITE        298
FT                   /note="For beta-ketoacyl synthase activity"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01348"
FT   ACT_SITE        333
FT                   /note="For beta-ketoacyl synthase activity"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01348"
SQ   SEQUENCE   406 AA;  42613 MW;  489D8BAD23E78113 CRC64;
     MKRAVITGLG IVSSIGNNQQ EVLASLREGR SGITFSQELK DSGMRSHVWG NVKLDTTGLI
     DRKVVRFMSD ASIYAFLSME QAIADAGLSP EAYQNNPRVG LIAGSGGGSP RFQVFGADAM
     RGPRGLKAVG PYVVTKAMAS GVSACLATPF KIHGVNYSIS SACATSAHCI GNAVEQIQLG
     KQDIVFAGGG EELCWEMACE FDAMGALSTK YNDTPEKASR TYDAHRDGFV IAGGGGMVVV
     EELEHALARG AHIYAEIVGY GATSDGADMV APSGEGAVRC MKMAMHGVDT PIDYLNSHGT
     STPVGDVKEL AAIREVFGDK SPAISATKAM TGHSLGAAGV QEAIYSLLML EHGFIAPSIN
     IEELDEQAAG LNIVTETTDR ELTTVMSNSF GFGGTNATLV MRKLKD
//