ID   FABB_HAEIN              Reviewed;         406 AA.
AC   P43710;
DT   01-NOV-1995, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1995, sequence version 1.
DT   27-MAR-2024, entry version 136.
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=HI_1533;
OS   Haemophilus influenzae (strain ATCC 51907 / DSM 11121 / KW20 / Rd).
OC   Bacteria; Pseudomonadota; Gammaproteobacteria; Pasteurellales;
OC   Pasteurellaceae; Haemophilus.
OX   NCBI_TaxID=71421;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 51907 / DSM 11121 / KW20 / Rd;
RX   PubMed=7542800; DOI=10.1126/science.7542800;
RA   Fleischmann R.D., Adams M.D., White O., Clayton R.A., Kirkness E.F.,
RA   Kerlavage A.R., Bult C.J., Tomb J.-F., Dougherty B.A., Merrick J.M.,
RA   McKenney K., Sutton G.G., FitzHugh W., Fields C.A., Gocayne J.D.,
RA   Scott J.D., Shirley R., Liu L.-I., Glodek A., Kelley J.M., Weidman J.F.,
RA   Phillips C.A., Spriggs T., Hedblom E., Cotton M.D., Utterback T.R.,
RA   Hanna M.C., Nguyen D.T., Saudek D.M., Brandon R.C., Fine L.D.,
RA   Fritchman J.L., Fuhrmann J.L., Geoghagen N.S.M., Gnehm C.L., McDonald L.A.,
RA   Small K.V., Fraser C.M., Smith H.O., Venter J.C.;
RT   "Whole-genome random sequencing and assembly of Haemophilus influenzae
RT   Rd.";
RL   Science 269:496-512(1995).
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; L42023; AAC23183.1; -; Genomic_DNA.
DR   PIR; A64128; A64128.
DR   RefSeq; NP_439682.1; NC_000907.1.
DR   AlphaFoldDB; P43710; -.
DR   SMR; P43710; -.
DR   STRING; 71421.HI_1533; -.
DR   EnsemblBacteria; AAC23183; AAC23183; HI_1533.
DR   KEGG; hin:HI_1533; -.
DR   PATRIC; fig|71421.8.peg.1604; -.
DR   eggNOG; COG0304; Bacteria.
DR   HOGENOM; CLU_000022_69_2_6; -.
DR   OrthoDB; 9808669at2; -.
DR   PhylomeDB; P43710; -.
DR   BioCyc; HINF71421:G1GJ1-1555-MONOMER; -.
DR   UniPathway; UPA00094; -.
DR   Proteomes; UP000000579; Chromosome.
DR   GO; GO:0005829; C:cytosol; IBA:GO_Central.
DR   GO; GO:0004315; F:3-oxoacyl-[acyl-carrier-protein] synthase activity; IBA:GO_Central.
DR   GO; GO:0006633; P:fatty acid biosynthetic process; IBA:GO_Central.
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_0000180313"
FT   DOMAIN          1..403
FT                   /note="Ketosynthase family 3 (KS3)"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01348"
FT   ACT_SITE        162
FT                   /note="For beta-ketoacyl synthase activity"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01348"
FT   ACT_SITE        297
FT                   /note="For beta-ketoacyl synthase activity"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01348"
FT   ACT_SITE        332
FT                   /note="For beta-ketoacyl synthase activity"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01348"
SQ   SEQUENCE   406 AA;  42649 MW;  A17B8673156FDDAF CRC64;
     MRRTVITGFG IISSIGNNKE EVLASLKAGK SGIEVVPEFV EMNMRSHVAG TIKLNPSEHI
     DRKVFRFMGD AAAYAYLSMR EAIEDAGLTE DQVSNDRTGL VIGAGTGSAH NQLVACDAVR
     GPRGVKAIGP YAVTKTMASS VSACLATPYK IRGVNYSMSS ACATSAHCIG HAVELIQLGK
     QDVVFAGGAE ELSWECATEF DAMGAVSTKY NETPEKASRA YDANRDGFVI AGGGAVVVVE
     ELEHALARGA KIYAEIVGYG ATSDGYDMVA PSGEGAERCM KQAMATVDTP IDYINVHGTS
     TPVGDVKELG AIKNVFGDKI PAISSTKSMT GHSLGAAGAH EAIYTLLMLD NDFIAPSINI
     ETLDEAAEGC NIVTETKENA GLQTVMSNSF GFGGTNATLI FKRYNG
//