P0A6R0 · FABH_ECOLI

  • Protein
    Beta-ketoacyl-[acyl-carrier-protein] synthase III
  • Gene
    fabH
  • Status
    UniProtKB reviewed (Swiss-Prot)
  • Amino acids
  • Protein existence
    Evidence at protein level
  • Annotation score
    5/5

Function

function

Catalyzes the condensation reaction of fatty acid synthesis by the addition to an acyl acceptor of two carbons from malonyl-ACP. Catalyzes the first condensation reaction which initiates fatty acid synthesis and may therefore play a role in governing the total rate of fatty acid production. Possesses both acetoacetyl-ACP synthase and acetyl transacylase activities. Has some substrate specificity for acetyl-CoA. Its substrate specificity determines the biosynthesis of straight-chain of fatty acids instead of branched-chain (PubMed:10629181, PubMed:7592873, PubMed:8631920, PubMed:8910376).
Can also use propionyl-CoA, with lower efficiency (PubMed:10629181, PubMed:8631920).

Catalytic activity

Activity regulation

Negatively regulated by acyl-ACP, possibly by binding to either the free enzyme or the acyl-enzyme intermediate (PubMed:8631920).
Inhibited by the SB418011 antibiotic (PubMed:11375394).
Not inhibited by cerulenin, and weakly inhibited by thiolactomycin (PubMed:11375394).

Kinetics

KM SUBSTRATE pH TEMPERATURE[C] NOTES EVIDENCE
40 μMacetyl-CoA
5 μMmalonyl-[ACP]

Pathway

Lipid metabolism; fatty acid biosynthesis.

Features

Showing features for active site.

TypeIDPosition(s)Description
Active site112
Active site244
Active site274

GO annotations

AspectTerm
Cellular Componentcytosol
Molecular Function3-oxoacyl-[acyl-carrier-protein] synthase activity
Molecular Functionbeta-ketoacyl-acyl-carrier-protein synthase III activity
Biological Processfatty acid biosynthetic process
Biological Processfatty acid metabolic process

Keywords

Enzyme and pathway databases

Chemistry

Names & Taxonomy

Protein names

  • Recommended name
    Beta-ketoacyl-[acyl-carrier-protein] synthase III
  • EC number
  • Short names
    Beta-ketoacyl-ACP synthase III
    ; KAS III
  • Alternative names
    • 3-oxoacyl-[acyl-carrier-protein] synthase 3
    • 3-oxoacyl-[acyl-carrier-protein] synthase III
    • EcFabH

Gene names

    • Name
      fabH
    • Ordered locus names
      b1091, JW1077

Organism names

  • Taxonomic identifier
  • Strains
    • K12
    • K12 / MG1655 / ATCC 47076
    • K12 / W3110 / ATCC 27325 / DSM 5911
  • Taxonomic lineage
    Bacteria > Pseudomonadota > Gammaproteobacteria > Enterobacterales > Enterobacteriaceae > Escherichia

Accessions

  • Primary accession
    P0A6R0
  • Secondary accessions
    • P24249

Proteomes

Subcellular Location

Keywords

Phenotypes & Variants

Features

Showing features for mutagenesis.

TypeIDPosition(s)Description
Mutagenesis112Loss of activity.
Mutagenesis214Strongly reduces the binding to malonyl-ACP but not that of the substrate.
Mutagenesis244Loss of activity.
Mutagenesis249Abolishes the binding to malonyl-ACP but not that of the substrate.
Mutagenesis253Abolishes both binding to malonyl-ACP and binding to substrate.
Mutagenesis256-257Strongly reduces both binding to malonyl-ACP and binding to substrate.
Mutagenesis256-257Abolishes the binding to malonyl-ACP but not that of the substrate.
Mutagenesis274Loss of activity.

Chemistry

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00001104241-317Beta-ketoacyl-[acyl-carrier-protein] synthase III

Proteomic databases

PTM databases

Interaction

Subunit

Homodimer.

Protein-protein interaction databases

Family & Domains

Features

Showing features for region.

TypeIDPosition(s)Description
Region245-249ACP-binding

Domain

The last Arg residue of the ACP-binding site is essential for the weak association between ACP/AcpP and FabH.

Sequence similarities

Belongs to the thiolase-like superfamily. FabH family.

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    317
  • Mass (Da)
    33,515
  • Last updated
    2005-05-10 v1
  • Checksum
    BF3192CFF36023D3
MYTKIIGTGSYLPEQVRTNADLEKMVDTSDEWIVTRTGIRERHIAAPNETVSTMGFEAATRAIEMAGIEKDQIGLIVVATTSATHAFPSAACQIQSMLGIKGCPAFDVAAACAGFTYALSVADQYVKSGAVKYALVVGSDVLARTCDPTDRGTIIIFGDGAGAAVLAASEEPGIISTHLHADGSYGELLTLPNADRVNPENSIHLTMAGNEVFKVAVTELAHIVDETLAANNLDRSQLDWLVPHQANLRIISATAKKLGMSMDNVVVTLDRHGNTSAASVPCALDEAVRDGRIKPGQLVLLEAFGGGFTWGSALVRF

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
M77744
EMBL· GenBank· DDBJ
AAA23749.1
EMBL· GenBank· DDBJ
Genomic DNA
M96793
EMBL· GenBank· DDBJ
AAB59065.1
EMBL· GenBank· DDBJ
Genomic DNA
U00096
EMBL· GenBank· DDBJ
AAC74175.1
EMBL· GenBank· DDBJ
Genomic DNA
AP009048
EMBL· GenBank· DDBJ
BAA35899.2
EMBL· GenBank· DDBJ
Genomic DNA
M87040
EMBL· GenBank· DDBJ
AAA23741.1
EMBL· GenBank· DDBJ
Genomic DNA
Z11565
EMBL· GenBank· DDBJ
CAA77659.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

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