Q9F6D4 · FABH_STRLI
- ProteinBeta-ketoacyl-[acyl-carrier-protein] synthase III
- GenefabH
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids339 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
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 (PubMed:11732905).
Propionyl-CoA and isobutyryl-CoA were the two most preferred substrates, although acetyl-CoA and butyryl-CoA could also be accepted and elongated (PubMed:11732905).
Involved in the biosynthesis of R1128 polyketide (PubMed:11732905).
Propionyl-CoA and isobutyryl-CoA were the two most preferred substrates, although acetyl-CoA and butyryl-CoA could also be accepted and elongated (PubMed:11732905).
Involved in the biosynthesis of R1128 polyketide (PubMed:11732905).
Catalytic activity
- H+ + malonyl-[ACP] + propanoyl-CoA = 3-oxopentanoyl-[ACP] + CO2 + CoAThis reaction proceeds in the forward direction.
- butanoyl-CoA + H+ + malonyl-[ACP] = 3-oxohexanoyl-[ACP] + CO2 + CoAThis reaction proceeds in the forward direction.
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
26 μM | propanoyl-CoA | |||||
184 μM | butanoyl-CoA | |||||
230 μM | acetyl-CoA |
kcat is 74 min-1 with propanoyl-CoA as substrate. kcat is 113 min-1 with butanoyl-CoA as substrate. kcat is 58 min-1 with acetyl-CoA as substrate.
Pathway
Lipid metabolism; fatty acid biosynthesis.
Features
Showing features for active site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Active site | 121 | |||||
Sequence: C | ||||||
Active site | 257 | |||||
Sequence: H | ||||||
Active site | 288 | |||||
Sequence: N |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | cytoplasm | |
Molecular Function | 3-oxoacyl-[acyl-carrier-protein] synthase activity | |
Molecular Function | beta-ketoacyl-acyl-carrier-protein synthase III activity | |
Biological Process | fatty acid biosynthetic process |
Keywords
- Molecular function
- Biological process
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameBeta-ketoacyl-[acyl-carrier-protein] synthase III
- EC number
- Short namesBeta-ketoacyl-ACP synthase III ; KAS III
- Alternative names
Gene names
Organism names
- Organism
- Taxonomic lineageBacteria > Actinomycetota > Actinomycetes > Kitasatosporales > Streptomycetaceae > Streptomyces
Accessions
- Primary accessionQ9F6D4
Subcellular Location
Phenotypes & Variants
Chemistry
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000110489 | 1-339 | Beta-ketoacyl-[acyl-carrier-protein] synthase III | |||
Sequence: MPGLRVPERRFSRVLGVGSYRPRREVSNKEVCTWIDSTEEWIETRTGIRSRRIAEPDETIQVMGVAASRRALEHAGVDPAEIDLVVVSTMTNFVHTPPLSVAIAHELGADNAGGFDLSAACAGFCHALSIAADAVESGGSRHVLVVATERMTDVIDLADRSLSFLFGDGAGAAVVGPSDVPGIGPVVRGIDGTGLGSLHMSSSWDQYVEDPSVGRPALVMDGKRVFRWAVADVVPAAREALEVAGLTVGDLVAFVPHQANLRIIDVLVDRLGVPEHVVVSRDAEDTGNTSSASVALALDRLVRSGAVPGGGPALMIGFGAGLSYAGQALLLPDPPSTPA |
Interaction
Subunit
Homodimer.
Structure
Family & Domains
Features
Showing features for region.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Region | 258-262 | ACP-binding | ||||
Sequence: QANLR |
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.
Family and domain databases
Sequence
- Sequence statusComplete
- Length339
- Mass (Da)35,392
- Last updated2001-03-01 v1
- ChecksumF0CA49FD80A7A26D
Keywords
- Technical term