ID   FABH_METCA              Reviewed;         321 AA.
AC   Q606L3;
DT   20-MAY-2008, integrated into UniProtKB/Swiss-Prot.
DT   23-NOV-2004, sequence version 1.
DT   25-MAY-2022, entry version 100.
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=MCA2003;
OS   Methylococcus capsulatus (strain ATCC 33009 / NCIMB 11132 / Bath).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Methylococcales;
OC   Methylococcaceae; Methylococcus.
OX   NCBI_TaxID=243233;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 33009 / NCIMB 11132 / Bath;
RX   PubMed=15383840; DOI=10.1371/journal.pbio.0020303;
RA   Ward N.L., Larsen O., Sakwa J., Bruseth L., Khouri H.M., Durkin A.S.,
RA   Dimitrov G., Jiang L., Scanlan D., Kang K.H., Lewis M.R., Nelson K.E.,
RA   Methe B.A., Wu M., Heidelberg J.F., Paulsen I.T., Fouts D.E., Ravel J.,
RA   Tettelin H., Ren Q., Read T.D., DeBoy R.T., Seshadri R., Salzberg S.L.,
RA   Jensen H.B., Birkeland N.K., Nelson W.C., Dodson R.J., Grindhaug S.H.,
RA   Holt I.E., Eidhammer I., Jonasen I., Vanaken S., Utterback T.R.,
RA   Feldblyum T.V., Fraser C.M., Lillehaug J.R., Eisen J.A.;
RT   "Genomic insights into methanotrophy: the complete genome sequence of
RT   Methylococcus capsulatus (Bath).";
RL   PLoS Biol. 2:1616-1628(2004).
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}.
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; AE017282; AAU91776.1; -; Genomic_DNA.
DR   RefSeq; WP_010961248.1; NC_002977.6.
DR   AlphaFoldDB; Q606L3; -.
DR   SMR; Q606L3; -.
DR   STRING; 243233.MCA2003; -.
DR   PRIDE; Q606L3; -.
DR   EnsemblBacteria; AAU91776; AAU91776; MCA2003.
DR   KEGG; mca:MCA2003; -.
DR   eggNOG; COG0332; Bacteria.
DR   HOGENOM; CLU_039592_3_1_6; -.
DR   OMA; WGSEGDK; -.
DR   OrthoDB; 872193at2; -.
DR   UniPathway; UPA00094; -.
DR   Proteomes; UP000006821; 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;
KW   Reference proteome; Transferase.
FT   CHAIN           1..321
FT                   /note="3-oxoacyl-[acyl-carrier-protein] synthase 3"
FT                   /id="PRO_1000088314"
FT   REGION          249..253
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        248
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01815"
FT   ACT_SITE        278
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01815"
SQ   SEQUENCE   321 AA;  34697 MW;  97329C43DCCCE532 CRC64;
     MSRYSRIAGT GGYLPRQVVT NDDLAMRVET SDEWIVERTG IRRRHIAAAD ETASSMAEIA
     SRQALEAAAI DPHDLDLIIL ATSSPDRVFP STACLLQQRL GVRSCAAFDV QAACSGFIFA
     LSIADQYISA GNANRVLVVG TEVNSRSVDW DDRSTCILFG DGAGAVVLES ATEPGIMSTH
     IHSDGHYQDL LYLPNPASNG EGSDESRTIR MQGSEVFKVA VNTLGRIVDE TLEQNGLQKS
     DVDWLVPHQA NIRIIAATAK KLQLPMERVV VTVDEQGNTS SASIPLAFDE AVRDGRIKRG
     QTVLMEAFGG GFAWGSALLR Y